Professor Jerry Coyne can’t seem to leave the Adam and Eve question alone. In a recent post, Professor Coyne criticizes Bryan College in Dayton, Tennessee, for requiring its teaching professors to sign an updated “statement of belief” which, for the first time, explicitly affirms the existence of an historical Adam and Eve. Since Bryan College describes itself as “a nondenominational evangelical Christian college named after William Jennings Bryan: statesman, orator, and renowned prosecuting attorney in the famous Scopes Evolution Trial,” this requirement should hardly occasion surprise. What would be surprising is if the college didn’t require its professors to believe in a literal Adam and Eve.
In a related post published late last year, Coyne explains in detail why he is convinced that science has ruled out the existence of Adam and Eve:
The facts first. Sheehan et al., building on an earlier paper by Li and Durbin (references below), calculated that the minimum population size associated with the worldwide expansion of humans out of Africa about 60,000 years ago was 2,250 individuals, while the population that remained in Africa was no smaller than about 10,000 individuals. For population geneticists, this is the “effective population size,” invariably smaller than the census size, so these are minimum estimates, and ones derived from conservative assumptions. The population sizes are estimated by back-calculating (based on reasonable estimates of mutation rates and other parameters) how small an ancestral population could be and still give rise to the observed high level of genetic variation in our species.
Note: 2,500 is larger than two.
This means, of course, that Adam and Eve couldn’t have been the literal ancestors of all humanity.
Evidently math is not Professor Coyne’s forte.
Note: 2,500 isn’t the same as 2,250.
Note: 2,250 + 10,000 = 12,250.
The math lesson is over.
Coyne goes on to say that even these figures are under-estimates: they represent “the ‘effective population size,’ invariably smaller than the census size.”
I invite readers to have a look at the following article by Luke J. Harmon and Stanton Braude, of Princeton University:
Conservation of Small Populations: Effective Population Sizes, Inbreeding,
and the 50/500 Rule
I shall quote a brief extract:
There is no such thing as “the effective size” of a population. Different effective population sizes help us to estimate the impact of different forces. The effective size you estimate will depend on the scientific question you are trying to address (Box 12.1). Estimating the appropriate effective population size is crucial in biology; in most (but not all) cases, effective population size will be smaller than the actual number of organisms in the population. Think for a moment about why
this is so. A conservative rule of thumb used by some biologists is
that N_e [the effective population size – VJT] is usually about one-fifth of the total population size (Mace and Lande, 1991). Using such a rough estimate is risky because N_e can be larger than the census size of the population, depending on the history of the population and the particular N_e under consideration.
It’s rather embarrassing when a biology professor makes mistakes in his own field, isn’t it?
UPDATE: A final suggestion for Professor Coyne. Coyne claims that the effective population sizes he cites are “based on reasonable estimates of mutation rates.” Coyne is assuming here that the mutations are natural and undirected. If Coyne wants to refute the Adam and Eve hypothesis as entertained by believers in intelligently guided evolution, then the question he really should be asking himself is: what would the effective population size need to be, if the mutations that gave rise to the human line were artificial and directed?
Cut him some slack, he’s an evolutionary biologist. He’s far closer to a phrenologist than a physicist when you get right down to it.
Maybe if the good doctor understood that Adam and Eve were just two members of a larger population, he might accept the fact that Eve is the mother all living humans on the planet today. Genealogy 101.
Isn’t part of the issue the assumed genetic diversity of the mitochondrial Eve and Y-chromosomal Adam?
-Q
Biologists, Please correct me if this would make no difference whatsoever, but to me if you want to concretely prove that Adam and Eve didn’t exist you can’t use existing population models. The bible has 3 variables that you’d have to consider. 1. Adam and Eve (1 human couple) 2. Adam and Eve were both supposedly perfect. 3. Subsequent generations of humans had near perfect DNA and lived to be much older than people today, the most famous being Methuselah living til the age of 969. If you are going to model a population and prove Adam and Eve didn’t exist wouldn’t you have to add in those factors?
fryether:
You have to remember that most secular “rebuttals” of Biblical claims consist of inserting a secular premise as quietly as possible into the mix of Biblical ideas, and then showing that the mix is self-contradictory.
No straw man is safe!
As a poster said here. man lived for hundreds of years before/after the flood and the females had maybe hundreds of children.
An example are the Hebrews. From 70 at Joseph’s time they came in four hundred years to 3 million or so at the exodus,.
We didn’t come out of africa. Were we black etc. did we lose african features.
its so dumb speculative its embarrassing for their sake.
It’s my understanding that we all started out as brown. Mutations resulted in some people having less melanin, others more.
I once saw a Smithsonian exhibit with tiles that matched all the shades of skin color in humans. There were hundreds of tiles ranging from coal black to an extreme white and everything in between.
-Q
What evolutionists like Coyne and Joe Felsenstein fail to realize is that with Creation there would be an intial burst of rapid evolution to fill the niches as well as create diversity. With Creation there wasn’t any waiting for chance mutations, it was a prescibed evolution. And that means evolutionary methodology does NOT apply, yet they want to use it anyway.
And that is why they will continue to fail.
The following paper and video by Dr. Robert Carter totally dismantles the ‘minimum population size’ argument.
CMI also has a excellent video of the preceding paper by Dr. Carter, that makes the technical aspects of the paper much easier to understand;
(Of note: although I don’t agree with the extreme 6000 year Young Earth model used as a starting presumption in the paper ans video for deriving the graphs, the model, none-the-less, can be amended quite comfortably to a longer time period. Which I, personally, think provides a much more ‘comfortable’ fit to the overall body of genetic evidence).
As to large genetic diversity being harbored in two founding members of a species, Darwinists are always ‘surprised’ when an ancient lineage of a species is found to be more genetically robust than the younger lineages,,,
These following studies and video, on Cichlid fishes, are evidence of the ‘limited and rapid variation from a parent kind’ that would be expected in the ‘top down’ design model:
also of note:
Dogs, Dawkins infamous example of macroevolution,,,
are perhaps the best example of large genetic diversity being harbored in a few (very possibly two?) founding members of a species:
As well, a non-Darwinian process of epigenetic modification has now been implicated in the rapid domestication of chickens:
More evidence for rapid radiations from a parent species can be found here:
Perhaps the best evidence we have from the fossil record for this ‘top down’ loss of genetic diversity we would expect from the design perspective is seen from the study of trilobite fossils. Here is an article on the “surprising” loss of variation and diversity for trilobites over the 270 million year time span that trilobites were found in the fossil record, prior to their total extinction from the fossil record about 250 million years ago.
As well humans themselves are shown to be losing Genetic Diversity not gaining it even though they now have a large population size:
Apart from point-scoring (which Coyne does enough of too, but doesn’t interest me much) this doesn’t make a substantive difffernce to the studies.
The only Nes that are likely to overestimate the census population size related to variance in offspring per individual (relevant to captive populations, but not really wild ones) and variance in population size. This latter one means the effective populatin size of a population right at the point of a bottle neck would be greater than it’s census size. Turned around, to explain a population growing from 2 to 6 billion in 10,000 years it would give us a modern effective population size of 400 or so. Many times lower than the observed.
Of course, you can create some after-the-fact justification that keeps a literal Adam and Eve if you want (just like you can claim the world was created yesterday complete with memories), it’s just that there is no scientific support for that idea.
wd400
The point is this- it is a plausible hypothesis that there was literally, one woman from which all humanity has descended, and that scenario is precisely what the Bible claims.
The fun part is the tree thinking aspect, right? Interestingly, evolutionary biology is obsessed with tree building, and it just so happens, several models can be constructed that precisely fit natural history, as explained by secular science, and predicted by the holy scriptures.
The point is this- it is a plausible hypothesis that there was literally, one woman from which all humanity has descended,
Do you mean ‘mitochondrial Eve’? It’s an inevtiable consequence of finite population sizes that someone is the common ancestor of out matralines (and indeed, the same applies to all species). I’m not sure how that meets a prediction of the scriptures. Perhaps I’m not understanding your point?
There is significant congruence between the findings of secular science, and biblical predictions in the book of Genesis, and in particular, in regards to the time-line of human evolution.
If you are interested in more information, Daniel Friedmann has written 2 short books on the subject, “The Genesis One Code”, and more recently, “The Broken Gift”.
I believe Mr. Friedmann is on the right track, but also believe better and more precise models are coming soon, once the Biblical parable embedded in Genesis is unlocked.
Without knowing what these apparent similarities are there is a little I can say about them. But it’s pretty clear that genetic data doesn’t support a literal Adam and Eve as co-founders of humanity, which was obstensibly the point of this thread?
wd400 confidently claims that:
And just what genetic evidence do you base such confidence on? The genetic similarity between chimps and Humans is turning out to be far less that what we were originally misled to believe by neo-Darwinists:
Even ignoring the subjective bias of ‘various methodological factors’ that Darwinists introduce into these similarity studies, the first inkling, at least for me, that something was terribly amiss with the oft quoted 99% similarity figure was this,,,
this had caught my eye in 2008,,,
In late 2011 Jeffrey P. Tomkins, using an extremely conservative approach, reached the figure of 87% similarity:
Then last year, 2013, with better resolution of data, and still using an extremely conservative approach, Tomkins reached the figure of 70% genetic similarity between chimps and humans:
Here a secular source comments on the Y chromosome:
Moreover, as if that was not devastating enough to the 99% similarity myth, a large percentage of completely unique orphan genes (10 to 30%,, no one really knows the exact percentage difference yet), with no sequence homology whatsoever, are now being found in each new genome that is sequenced, including humans and chimps:
Moreover, genetic similarity is now known to be broadly similar across what are suppose to be widely divergent species,
Yet what accounts for such drastic differences in the species if the gene count is basically the same across widely divergent species (as well as supposedly closely related species)? Genomic regulatory systems do. For instance, alternative splicing, which is part of the extremely complex genomic regulatory system, is found to be species specific:
Yet variations to genomic regulatory systems are found to to catastrophic to (bottom up) neo-Darwinian scenarios because,,
verse and music:
Is evolution pseudoscience?
Excerpt:,,, Thus, of the ten characteristics of pseudoscience listed in the Skeptic’s Dictionary, evolution meets nine. Few other pseudosciences – astrology, astral projection, alien abduction, crystal power, or whatever — would meet so many.
http://creation.com/is-evolution-pseudoscience
Darwinian Evolution is a Pseudo-Science – Part II
https://docs.google.com/document/d/1oaPcK-KCppBztIJmXUBXTvZTZ5lHV4Qg_pnzmvVL2Qw/edit
Jerry Coyne as quoted in the Opening Post:
This certainly is not an area of expertise on my part, but it looks like Dr. Coyne couldn’t have muddled it up any worse than he did.
=======>
From the version of the Sheehan paper that is available online, we know that she is employing a “coalescent method.”
[From the abstract of the Sheehan paper of March 2013:]
Now, what does Wikipedia tell us about such methods?
[From Wikipedia:]
From these equations, it is quite clear that the “coalescent method” absolutely needs a number for the effective population size (= N_e). One can employ the method to sort of ‘back in’ to a number which works in known ways in other instances.
So, effective population sizes are part and parcel of “coalescent methods.” Period. Nothing new here. Nothing important.
==========>
However, here’s what Sheehan, et. al. have to say in their paper:
[From the Sheehan paper first submitted in March 2013:]
From the bold-lettered sentences, one can infer that going back 117,000 years, the effective population size leading up to today’s Europeans shrank from N_e of 28,000 within the African lineage, to that of 2,250. Further back in time, both lineages would have been ‘coalesced,’ and one is free to assume that the effective population size as one goes further back in time would have been 28,000.
Now, Dr. Coyne appears to have made three errors:
(1) He supposes that the original population size of human ancestry was 2,250, instead of the 28,000 that the article implies;
(2) He’s confused the “bottle-neck” that occurred in the “out of Africa” lineage 117,000 years ago, with that of the MCRA of ALL humans, which goes further back in time;
and (3) He somehow thinks that what this particular modification of an earlier “coalescent method” has done is to give us the actual population size of humans, when, in fact, it is quite clear that the methodology employed by such “coalescent methods” cannot go back any farther than the MCRA, which only means that the genetics involved in leading up to the ‘original’ population is blind to this particular method, and so we don’t know how many generations were involved before the MCRA arose. Since homozygozity at a location is presumed by the method as a starting block, along with that of random drift, fixation of an allele via random drift takes, on average, 4N_e, or, in the case of 28,000 individuals, 112,000 generations!!! [BTW, 2^15=32,000 (approx.), so only 15 generations are needed to go from “Adam and Eve” to a population size of 28,000!]
And, Jerry, 32,000 is greater than 28,000!
==========>
One final note:
This method uses a section of Chromosome #1 which is in a non-genic area, so that the “confounding” effects of “natural selection” can be discounted (i.e., as I said above, they assume random genetic drift). But we now know that even non-coding DNA is functional, and hence, should be preserved and affect by NS. So there is some dubious note to the method employed.
The MRCA of humanity (or at least, of ‘contacted’ peoples, which can contribute to genetic studies) likely lived within the last 5,000 years. So these methods can certainly reach further back than the the last common ancestor of the population in question. Indeed the Li and Durbin papers goes back further than a million years without detecting a major bottleneck.
I don’t know what the 2^15 business is meant to prove, but a population that grew like that would have an Ne of ~15
wd400, I find it funny that you place enough confidence in the mathematics of population genetics, (with underlying Darwinian assumptions of course), to tell you that Adam and Eve could not have existed, but you don’t place any confidence in the mathematics of population genetics when the math tells you tells you that Darwinian evolution is effectively falsified:
Why the inconsistency in how you weight the results from the mathematics of population genetics wd400? An unbiased observer might conclude that you are letting your personal philosophical bias dictate how you judge the mathematical evidence!
Is evolution pseudoscience?
Excerpt:,,, Thus, of the ten characteristics of pseudoscience listed in the Skeptic’s Dictionary, evolution meets nine. Few other pseudosciences – astrology, astral projection, alien abduction, crystal power, or whatever — would meet so many.
http://creation.com/is-evolution-pseudoscience
Darwinian Evolution is a Pseudo-Science – Part II
https://docs.google.com/document/d/1oaPcK-KCppBztIJmXUBXTvZTZ5lHV4Qg_pnzmvVL2Qw/edit
WD400
You misunderstood what I meant.
Yes, of course, using the “coalescent method”, one travels from one ‘coalescent’ to another; or, from one ‘MCRA’ to the next. Wherever that process ends, you’re left with a ‘MCRA,’ and it is as far back as you can go. We then have no information of what happened before the establishment of that last ‘MCRA.’ Coyne’s attempt to extrapolate from that ‘effective population’ to the non-existence of “Adam and Eve” is still as wrong as ever.
As to Li and Durbin, and their finding of no “bottleneck” even as far back as a million years, let’s remember this! Sheehan’s study is designed to overcome problems they perceived in the model used by Li and Durban. Again, this has no bearing whatsoever on Coyne’s errors.
Lastly, you write:
How, exactly, did you arrive at a number of approx 15 for Ne?
Please stipulate. Numbers, please.
As to what I meant to prove, simply this: from one man and one woman, a population is reached in a very short number of generations. If I had assumed, for example, that Adam and Eve gave birth to ten children, who themselves, paired up and had 10 children as well, one would then arrive at a population size of 28,000 is much less than 15 generations. So, very generously, 15 generations is really all that is needed to reach Sheehan’s last ‘MCRA’. 15 generations is not enough time for any one mutation to arise and spread through the population, and thus serve as a ‘coalescent.’ 112,000 generations, on average, would be needed. And, using Coyne’s logic, 112,000 >>> 15. So, no extrapolations from the last ‘MCRA’ can be made, and, obviously, there’s enough time in generations for a single man and a single woman to give rise to Ne of 28,000 without it being detected.
Q.E.D.
Let me correct a number I’m using: I’ve used 1/4Ne as the probability of a mutation spreading via random genetic drift through a population. But this is for diploid populations. Since we’re considering haploid populations, this would then be 1/2Ne. So the above number of generations needed for a population of 28,000, that of 112,000, should be rather 58,000. The point I make is still every bit as evident.
How, exactly, did you arrive at a number of approx 15 for Ne?
It’s the harmonic mean of the census population sizes. In this case, as the number of generations (t) get’s large Ne approaches t as the numerator is the genometric series (approaching 1) and the denominator is t.
If a population really did grow from 2 to 32 000 the Ne would not be 32000 or anythng like it.
I should add, there are allels currently seggregating in human populations that coalesce deeper in time than the human-chimp speciation (http://www.sciencemag.org/cont.....1578.short). Very hard to see how you could include these w/ a literal adam and eve.
Again wd400 I am amazed at the severe bias you place on these mathematical models that are jerry-rigged to support your Darwinian philosophy,,,
and the total disregard you have towards any mathematics that show Darwinian evolution to be astronomically unlikely. You state:
Why wd400 are you not even more concerned with the fact that Darwinian evolution cannot account for the fixation of a single ‘coordinated mutation’:
wd400
Yes, that’s right. So, in the numerator you have: [1/2+1/4+1/8+1/16+….1/32,000 (approx)]/15.
But what if we say the population stabilizes at 28,000 for an additional four generations. Then, for the last seven generations we’d have: [1/8,000 + 1/16,000 + 1/32,000 + 1/28,000 + 1/28,000 + 1/28,000 + 1/28,000]/7 = (approx) 24,000 = Ne.
Your noting of the calculated Ne is a picayune detail and seems meant only to distract and to detract. Nothing more. We’re orders of magnitude away from any significance in terms of coalescence.
wd400:
I should add, there are allels currently seggregating in human populations that coalesce deeper in time than the human-chimp speciation (http://www.sciencemag.org/cont…..1578.short). Very hard to see how you could include these w/ a literal adam and eve.
Are you trying to change the subject?
You’ll notice that in the abstract of the paper they speak of NS acting over time.
The method of “coalescence” presumes “random genetic drift.” It turns off NS. So you’re trying to compare apples and oranges.
Did anyone say that common inheritance didn’t apply to Adam and Eve?
(BTW, I don’t believe in common descent for the simple reason that this presupposes that form A had to give birth to form A’ in some finely graded fashion, and not to some kind of new form B. Common inheritance simply says that transitions have as their basis what went before; i.e., A and B share commonalities of all sorts.)
The harmonic mean is number of elements divided by the sum of their reciprocals. A population that went from 2 to 32,000 then stabalised for 100 generatoins would have an Ne of… 100. You can’t slice out the midle section without including the ealier ones.
I’m certainly acting in bad faith – I honestly can’t understand how you think these calculations save a literal Adam and Eve.
The point about the ancient coalescnces is that these genes for which the version I have might might be more closely related to the version a chimp has than the one you have. Polumorphisms that were present before the human chimp split are still polymorphic.
(PaV’s confusion about the calculation of the harmonic mean is down to me – as I flipped the terms denominator and numerator while hasily editng my comment. The substantive point remains – rapidly growing populations have very low Ne which is dominated by the size of the bottleneck even if census population size later stabalises)
And again wd400, I have a very hard understanding how you can put such confidence in such a shabby ‘coalescent theory’ you are currently supporting:
As far as I can tell wd400 this ‘coalescent theory’, in which you are basing your conclusions as to whether there was an Adam and Eve or not, This theory of ‘genetic drift’, in which most mutations are assumed to be neutral, and, as PaV stated, Natural Selection is ‘turned off’, is nothing more than mathematical fantasy. In fact, Dr. Berlinski retorted to this ad hoc theory that you seem to place so much confidence in:
Dr. Hunter with a bit more restraint, and with a bit more clarity as to the shell game Darwinists are playing with the evidence, stated this in regards to this ‘coalescent theory’ in which most mutations are considered neutral:
wd400, even the assumption that mutations are neutral was not derived from empirical evidence, but was an assumption that was forced upon Darwinists by the math:
A graph featuring ‘Kimura’s Distribution’ being correctly used is shown in the following video:
Thus wd400, I certainly see no empirical warrant for the confidence you place in your assumption that most mutations are neutral (i.e. the confidence you place in ‘genetic drift’). Especially considering the fact that common sense, and empirical evidence itself, contradicts your unwarranted assumption that most mutations are neutral:
Thus wd400, without empirical warrant, in fact with empirical evidence contradicting your ‘neutral’ assumption, I find the mathematical model you place so much confidence in so as to inform you about man’s ancestry, to be nothing but an exercise in mathematical wish fulfillment! ,,, i.e. You have left the bounds of true empirical science and are practicing nothing more than pseudo-science!
ba77 concludes the following:
So, continuing in this vein, my question is why WD400 would continue to cling to Darwinism when the facts and the math have turned decisively against the idea?
There are several possibilities:
A. Strong desire to remain scientifically orthodox.
B. Reasonable scientific scepticism.
C. Fear of ridicule, ostracism, and career damage.
D. Aversion to the moral and philosophical consequences.
A. I would rule out A as a primary motivator. While it might be present to some degree, WD400’s posts are not consistent with the defensive nature of this position.
B. Similarly, I think we can also rule out B on the grounds that a reasonable person would admit the challenges posed by emerging genetic, epigenetic, and mathematical data. Still, an argument can be made that WD400 is simply presenting all the counter–arguments in preparation to a dramatic shift in outlook. A stronger argument can be made that WD400 is steeped in 19th century Darwinism, and, as a result, all facts are tainted by the Darwinistic paradigm.
C. This is certainly a valid and very real concern considering the professional carnage suffered by people who demonstrate even a neutral, unbiased treatment of people who agree with the Intelligent Design paradigm. Nevertheless, this motivator, like A is primarily defensive, and isn’t consistent with WD400’s posts.
D. This would explain the posts and strict, religious adherence to a theory from the age colonialism and the industrial revolution. But we’re still somewhat lacking in the vituperation department, so I don’t know . . .
Any ideas, ba77?
-Q
wd400
Was UCA an individual, or a population? And how can you know when? Maybe UCA is a trillion years old from another universe, eh?
But in all seriousness, I think you probably truly have genuine faith in naturalistic science, and perhaps love your science. Therefore, I vote for none of the above.
Opps, I guess it could be B?
“Any ideas, ba77?”
None really that I would hazard a guess on. It is not as if wd400 is too dense to understand that Darwinism is bankrupt. Thus I cannot fathom his primary motivation for refusing to be honest. The underlying motives of a man’s heart is, many times, a mystery that would make the deepest mysteries in Quantum Mechanics seem like child’s play by comparison
Querius, Thankfully there is One who does understand the human heart and is able to reach its deepest recesses.
Proverbs 15:11
Death and Destruction lie open before the LORD– how much more do human hearts!
Music:
Evanescence – My Heart Is Broken
http://www.vevo.com/watch/evan.....WV41100052
ba77,
The part I like the best is God’s promise of giving us a new heart that lets go of pride and selfish ambition and instead finds pure delight, amazement, appreciation, and reverence in discovering the designs hidden in nature—if only we are willing!
-Q
wd400:
If a population is steadily increasing, and then reaches some stabalized level, then please explain how you can then speak of a “bottle-neck.” How can something be constrained when it is steadily increasing to some greater level? Should the population shrink to some reduced level at some later time, then, yes, you can talk about a “bottle-neck.”
I study quantum mechanics. Do you think something as simple as an harmonic mean is going to through me for a loop? Please.
Where you go wrong is that you think these equations give us actual truth when, in fact, their educated guesses that involve making assumptions about a number of things. They’re just little tools—more like toys—that population geneticists use. To say that these types of equations constitute disproof of Adam and Eve is just silliness. Science isn’t God.
And, again, should I point out to you that this method involves RGD which, as you should know, prescinds NS; so think about what you’re saying: human populations arose through completely random methods. This is an absurd scientific statement on its face. And, where, exactly, should we be looking for Darwinism here?
Darwinists are wonderful. When it suits their purpose, they abandon their theory, and then tell others who dispute the theory that they don’t know what they’re talking about.
If a population is steadily increasing, and then reaches some stabalized level, then please explain how you can then speak of a “bottle-neck.”
The bottleneck is the very small starting size. That means the population will have much less diversity that one that has been at the present stable size for a very long time.
I study quantum mechanics. Do you think something as simple as an harmonic mean is going to through me for a loop? Please.
Well, you got it wrong…
To say that these types of equations constitute disproof of Adam and Eve is just silliness. Science isn’t God.
It’s not sillyness, and you yourself started by trying to use the tools to save the literal Adam and Eve. Of course someone cen beliefe in a lieteral Adam and Eve, but you can’t pretend the genetic evidence supports such a couple.
And, again, should I point out to you that this method involves RGD which, as you should know, prescinds NS; so think about what you’re saying: human populations arose through completely random methods. This is an absurd scientific statement on its face. And, where, exactly, should we be looking for Darwinism here?
Ok, what do you think would happen to an esimtate of population size if natural selection was operatin (which it is not, in most of the genome). Selection means fewer members of population contribute to the next generation than would otherwise be the case, so selection (positive or negative) makes Ne lower with repsect to the census population. In fact – scans of lowered Ne are one of means by which we can estimate historical selection.
Darwinists are wonderful. When it suits their purpose, they abandon their theory, and then tell others who dispute the theory that they don’t know what they’re talking about.
“Darwinists” are largely the invention of creationists. Evlutoinary biologists undertand that much of the variation in our genome can be best explained by neutral theory, other parts by selection. If someone can’t understand that modern evolutioary biology includes more than just natural selecton then they certainly don’t know what they’re talking about.
You just don’t understand evolution wd400! 🙂
wd400:
You didn’t answer the question. A “bottle-neck” OCCURS when a population’s size changes drastically shrinks from one generation to the next, or if it fluctuates wildly over time. You simply want to call the small starting size a “bottle-neck,” and no more. Remember, the coalescent method they employ can’t look beyond the ‘last’ effective popoulation size. It’s uncharted territory. You simply want to make the claim that this constitutes a ‘bottle-neck.’ You don’t get to make things up. If you look at the formula for Ne, it’s a summation. It doesn’t show a sum of minus infinity to plus infinity, or even zero to positive infinity. You have a starting population size, and an ending population size. That’s it. If you’re doing an experiment in the wild, or in the lab, you can keep track of all of this. But when they want to use molecular biology to go back in time, they simply back into these numbers.
Ignorance cannot be replaced with exact equations—which is what you’re trying to do. Sorry.
It’s one thing not to understand an equation, and quite another to make an algebra mistake, especially when you do it in a hurry so as not to waste any more time than is necessary.
But, in the end, who really got it wrong? You come up with an answer of roughly the inverse of 1/6, 15, and then say this is the effective population size. Does that number make much sense? No. Isn’t the true Ne closer to 32,000 than it is to 15? No common sense employed. Just plug in the formulas. Follow the recipe. Recite the dictionary words.
Here’s an example. Imagine 9,990 generations of population size 28,000, then followed by 10 generations of population size 100. Now think of 1 generation of population size 100, which then increases to 400 in the next generation, which then increases to 1,600 the next, and then increases to 6,400 in the fourth, 12,800 in the fifth, and 28,000 in the sixth and all the following up until the ten-thousandth generation.
Per the FORMULA, the second lineage would have a higher Ne, but both would be about the same. Now tell me, WHERE did the “bottle-neck” take place? You have no idea mathematically, and if you ventured to say the bottleneck occurred in the first generation, you’d be off by almost 10,000 generations! Do I make myself clear?
I used the tools so as to point out their limitations, something you don’t want to accept.
How does this respond to my statement. I’m sure population geneticists have plenty of toys. Look, face it, the methods employed are for the vast majority of the time are educated guesses and nothing more. Before gel-phoresis methods, Darwinists were sure that there would be very few sites where SNPs would be found. Wrong. Very Wrong. And they were using the very same logic you applied in the paragraph above. But why should that slow down a Darwinist?
A Darwinist is someone who believes in DARWIN’S theory of evolution. Do you believe in that theory, or not?
A “creationist” is largely the invention of Darwinists. I stopped telling people I wasn’t a “Creationist” but got tired of having to do it over and over. “Creationist”, with a small letter, is nothing more than the attempt by Darwinists to lump anyone who disagrees with Darwin’s theory into the same camp as those who take the first six days of ‘Creation’ to mean six literal solar days. When it is objected that the person doesn’t believe that, then the Darwinist simply switches from ‘upper case’ Creationist to ‘lower case’ creationist. Now I believe that God created the world. I’m sure that Ken Miller also believes that God created the world. He simply believes that God used NS and such in bringing the full diversity of life into being. But I’m not afforded such leeway. Why? Because, whereas Ken Miller accepts Darwin’s theory, I do not. So that doesn’t make him a ‘creationist’ while it does me.
So, the basic meaning of ‘creationist’ has really nothing at all to do with what one “believes” religiously, but, rather, whether or not one “believes” in Darwinism. IOW, you ERR in calling me a creationist—along with many others. But I DON’T ERR in calling you a Darwinist—-unless, of course, you want to tell everyone here and elsewhere that you really don’t believe in Darwin’s theory.
Many attempts have been made to understand genetics, some employ NS and some genetic drift, which has long been recognized as playing some role. But if you eliminate NS ENTIRELY, then Darwin is dead, and, guess what, then there is no longer any THEORY. What other theory of evolution has been proposed, exactly (not just some mechanism, but a full-blown theory. The only one I’m aware of is Margolis’ and now that of Shapiro)
Let me ask you a question, did Mendel believe in Darwinism, or not? Did Mendel believe in God, or not? Did he believe that God created the world, or not? Was Mendel a ‘creationist’? IOW, it was a religious person who was behind all of what you want to promote as sensible science.
Here is the ruination of population genetics. The genome of a moth: is it the genome of a moth, or of a butterfly?
Just mull that one over a bit. Two hugely different phenotypes and the EXACT SAME genotype. If it is genetically the same, identical in fact, than how in the world do you explain the huge phenotypic differences? I await a wonderful answer here.
PaV, while I read with your whole article with interest, and was pleased, it was the last part of your article that really caught my attention, namely:
I would certainly like to have a solid reference for that if you have it handy! 🙂
Response to John Wise – October 2010
Excerpt: But there are solid empirical grounds for arguing that changes in DNA alone cannot produce new organs or body plans. A technique called “saturation mutagenesis”1,2 has been used to produce every possible developmental mutation in fruit flies (Drosophila melanogaster),3,4,5 roundworms (Caenorhabditis elegans),6,7 and zebrafish (Danio rerio),8,9,10 and the same technique is now being applied to mice (Mus musculus).11,12 None of the evidence from these and numerous other studies of developmental mutations supports the neo-Darwinian dogma that DNA mutations can lead to new organs or body plans–because none of the observed developmental mutations benefit the organism.
http://www.evolutionnews.org/2.....38811.html
Hey wd400, You’re Going the Wrong Way – video
https://www.youtube.com/watch?v=_akwHYMdbsM
For neutral evolution, population size doesn’t matter, correct? At least not in terms of having a particular change becoming fixed in the population.
Dumb question about neutral evolution:
There are three basic types of changes: deleterious, beneficial, and neutral.
1. Deleterious everyone knows what will happen.
2. Beneficial can help the organism and be subject to selection.
3. Neutral is just that — neutral to the organism and invisible to selection.
It is argued by some that most changes/mutations are neutral. Let’s assume for a moment that is true.
Why then are neutral changes sometimes held up as an example of evolution? By very definition, they are neutral — meaning they are, by very definition, not causing any evolution.
Indeed, the existence of numerous neutral changes in an organism demonstrates that the organism robust against change. In other words, it is resistant to evolution.
All of this follows rather naturally and, it seems, inexorably from the idea of pervasive neutral changes/mutations.
Thus, at most, neutral changes are just that — neutral — and not relevant for evolution. On the other side, however, one could quite easily argue that neutral changes demonstrate that organisms can undergo significant perturbations in the genome and otherwise, while still not exhibiting any meaningful organismal change, and therefore neutral changes/mutations are actually evidence against the “plasticity” of organisms that is important to evolutionary theory.
Thoughts?
The theory of neutral evolution came about based on the question: “is the diversity in a species due to natural selection or lack thereof”. Then they began to explore things like Haldane’s dilemma, the cost of natural selection (i.e. how many individuals do you kill off to maintain features).
For example, with a genome of 4 giga base pairs, how many people do you have to kill off per generation to maintain conformity? If for example you have a mere 6 mutations per individual that deviate from a “good” configuration, every female human would have to give birth to 800 kids!
Thus, it became obvious most evolution had to be free of selection, if design appears, natural selection had to be mostly absent as a cause.
I provided sample calculations here at the bottom of the essay.
http://www.uncommondescent.com.....e-fittest/
Were my claims novel? Hardly, I got it from the evolutionists themselves, but it seems they prefer to let confusion reign lest IDists and creationists put two and two together and realize selection doesn’t much work as a theory of evolution.
Right. But with respect to neutral changes, it is called “evolution” only in a loose (and, frankly, slightly deceptive) sense, because, by definition, neutral changes aren’t causing evolution. At least not in any meaningful sense. It is “evolution” only if every change is evolution, in which case we have robbed the term of any substance. Evolution now means essentially “everything that happens”, even if it doesn’t affect the organism in the least.
By golly, I think you’ve got it. 🙂
If evolution = a change in allele frequency AND neutral mutations do not affect allele frequency, then no evolution takes place with neutral mutations.
However if you define evolution as descent with modification then neutral mutations are a modification and therefor evolution.
That said not all deletrious mutations get eliminated and beneficial is relative.
And with neutral mutations population size does matter wrt becoming fixed. The larger the population the less likely anything will become fixed. No one has ever confirmed Kimura’s equations- not in the wild.
Typically, evolution is loosely defined as “change over time.” Once you’re bullied into agreeing that you believe things change over time, you are “baptised” as an evolutionist. The next part is that you’re supposed to accept without criticism the entire corpus of just-so stories that range from plausible to hilarious.
One factor often overlooked is that a single beneficial mutation must occur in multiple individuals, a certain percentage of the population, without which chance alone will result in the mutation disappearing from the genome.
-Q
There’s a lot of comments here, so here are some brief and general answers.
1. Population size matters in neutral theory. Othersiwse neutral coalescent methods couldn’t establish historical population sizes. The special case in which population size vanishes in calculation is when we work out the rate at which new variants fix (or differences btweeen sister species accrue).
2. I don’t know why you would think neutral change was not evolutionary change. And neutral variants are alleles
3. PaV and others want to seem to want to pit neutral theory, and the fact most variants are not subject to selection against “Darwinism” as if onyl one can win. In fact, neutral nearly-neutral and selective models represent a contium. They simply explain the behaviour of genomes and genes and organism under different slection intensities. We can use what we know of biology to detect natural selection (indeed, neutral thoery provides teh null hypothesis for such tests) but we can also show that most genetic change is neutral. There is no conflict there.
4. The fact that most of the genome evolves close the neutral rate is certainly evidence that organisms can withstain mutations without fitness. That’s one fo the good arguemtns for junk DNA, for instance. BUt again, that doesn’t meant tehre aren’t genetic variants that are subject to selection.
5 One factor often overlooked is that a single beneficial mutation must occur in multiple individuals, a certain percentage of the population, without which chance alone will result in the mutation disappearing from the genom
Nah. Such “soft sweeps” may in fact be common. But nothng requires the same mutation to arise in multiple individuals before it is swept to fixation. Indeed, neutral theory shows us that mutations with no selective advantage can eventually take over a population.
BA77:
Sorry. I was in a terrible rush at the time. I don’t know how that error eluded me. I meant a worm and a butterfly, not a “moth and a butterfly.”
Sorry again. Wish I could edit that one out since someone might not read this post.
wd400:
That’s the propaganda anyway. But no one has shown such a thing.
But anyway, thanks for the correction as I wrongly thought that most neutral mutations, wrt Kimura, were in non-coding regions. That said we now know that so-called silent mutations aren’t silent at all. It all depends and that would affect the neutral theory.
wd400:
Really. Let’s remember that all of this is sort of dreamed up. These equations are chosen for various reasons. That doesn’t make them TRUTH STATEMENTS.
But, as usual, you’ve missed my point. I gave an example to two scenarios for a population having 10,000 generations. One starts out small and grows quickly. Almost 10,000 generations later, per the equation (not “truth statement”),under the scenario I depict, the “effective population size” would be the very same as for one that started out at 28,000 and remained the same for 9,990 generations, but then was decimated, and had a population size of only 100 for the last 10 generations. Isn’t it quite clear that this last scenario represents what is meant by a “bottleneck” while the other did not? Yet, basically the same numbers. Do you get it yet?
Look above at the formula for Probability of Coalescence. There are two variables: Ne and t=time. Now tell me, do they plug in a value of Ne and solve for time, or do they plug in a value for ‘t’ and then solve for Ne? Maybe this will help you see things more clearly.
You missed my point completely. So what if the Ne is slightly lower. It’s almost meaningless since you can’t look beyond it, and you have no way of knowing what, and how anything, happened.
My point was that Darwinists casually jettison the “theory of evolution”=Darwinism, when it suits their purposes. IOW, prove “evolution” happened no matter what means you employ, and no matter what contradictions it erects. And, of course, this “proof” is, like ‘beauty’ (and anything else that is SUBJECTIVE!) only in “the eye of the beholder.”
If you’re an “evolutionary biologist”, and want to move on from Darwin, that what, exactly, is the “theory” you employ? Can you explain this for all of us here at UD? Just exactly what is your theory. And, of course, since you’ve moved on from Darwin, don’t bother mentioning random variation and NS, because that’s Darwinism. So, give us your theory, please.
And, I suspect it will take many years, probably decades, well after my death, before my notions will be prove correct; however, when you say “abundant evidence for the operation of natural selection in genomes,” this would be better stated: “there is abundant evidence for the apparent operation of natural selection in genomes.”
I fully suspect that when the final chapter on all of this is written, we will discover that the genome ‘adapts’ itself to the environment, and the entire ‘adaptive’ process relies on information provided by the genome itself, and that NS—which is no more than lack of viability of an organism—is simply a by-product of the adaptive response.
Nevertheless, that biochemical pathways can be turned ‘on’ and turned ‘off’ via the decimation of a population doesn’t mean that this process can be used in a directed way for the building up of, let’s say, ‘new’ biochemical pathways.
As I’ve stated before, if a human being at age 5 can jump over a basketball, and at age 12 jump over a wheelbarrow, and at age 22 jump over an upright oil barrel, doesn’t mean that at age 75, he will be able to jump over roof-tops. Do you get my analogy?
P.S. I’ve stated over and over again, that if Darwin had titled his book “Origins of Adaptations,” I would find very little fault with it. But ‘adaptations’ do not ‘evolution’ make!
I find it almost astonishing that you can’t think this problem through.
The theory of evolution, =Darwinism in various forms, tells us that genetic change within the genome can build up over time and result in the kinds of changes in phenotype that we see in the fossil record over time.
And, yet, the EXACT, SAME GENOTYPE—-NO GENETIC DIFFERENCES–is responsible for two, entirely different–hugely different–phenotypes, including different morphology, locomotion, feeding habits, and instincts. The unavoidable conclusion is that morphological changes CANNOT be simply equated to genomic changes. And, in the case of the caterpillar and the butterfly, this is so glaringly apparent as to make nonsense of the field of population genetics.
Thanks, wd400:
Yes, I was referring to the fixation of new variants in the population. So, given a starting population, in order fix a number of new changes occurring in, say, a genome over time, the size of the population would presumably be irrelevant? I’m not arguing over coalescent methods, just trying to make sure I’m clear on the fixation of new variants.
Oh, sure. It is all “evolution.” As long as we are so loose with our definitions as to lump virtually everything that happens under the heading of “evolution.” And then we engage in the deceptive (whether purposeful or negligent) rhetoric of implying that these evidences of “evolution” demonstrate the truth of “evolution” broadly speaking. Things like new body plans, new functional systems, new information-rich sequences. All of which are the real fundamental requirements of producing new life forms on Earth, and none of which — by definition — come about through neutral changes.
This is the kind of muddled approach that leads many supporters to pound the table and proclaim the “fact of evolution!”, even though none of the real fundamental questions has ever been observed or demonstrated.
So, yes, we can call neutral changes “evolution.” As long as we are willing to acknowledge that evolution in that sense really means nothing of consequence and is just a surrogate for some change, any change, an observation that something happened.
We can use words like “neutral evolution” to try and bring the observation of neutral changes under the umbrella of evolution. But an objective review might suggest that, if anything, the existence of many neutral changes in an organism means that the organism is robust against substantive change — a real life example of not evolving in any meaningful sense.
Joe:
That said we now know that so-called silent mutations aren’t silent at all. It all depends and that would affect the neutral theory.
That’s right, Joe. It’s good that you’re pointing this out. Now, the Darwinists—oops, the “evolutionary biologists”—have another conundrum they must face. It’s never ending. As I say: “Another day, another bad day for Darwinism.”
PaV,
I really see no point in carrying this on. You said in your first post that you weren’t an expert in this field, and so it has proved.
I understand that in the scnarios you dreamed up the Ne (and so genetic diversity) would be approximately the same at the end. I don’t know why I shuold care. Again, if there had been a time in which the human population was 2 people in last million years these methods would detect it.
The rest is wild and whirling words. The idea that gene expression is important (polyphenism) is hardly new to evolutionary biology (Wilson and King famously suggested gene expression differences would be the principal differnces between humans and chimps in the 1970s). But gene expression differences are tehmselves driven by genes (regulatory sequences and tanscription factors and even fashionable but probably less important things like miRNA and DNA methyl-transferases).
“You said in your first post that you weren’t an expert in this field, and so it has proved.”
aka “You just don’t understand evolution’. 🙂
The Mismeasure of Man: Why Popular Ideas about Human-Chimp Comparisons Are Misleading or Wrong – Ann Gauger March 10, 2014
http://www.evolutionnews.org/2.....83011.html
wd400:
If those methods apply. That is the question and we say they do not.
wd400,
I watched the video of Dr. Robert Carter’s presentation, and he obviously takes these calculations seriously. So, I think I should afford them more propriety than I have so far.
Yes, they tell us something. And, yes, prima facie they point to a “population” and not “two people.” But Dr. Carter makes clear that, from a biblical point of view, at least two factors must be considered when interpreting the data. The first is the Biblical Flood, which, in all likelihood (I’m not a YEC) occurred after the last Ice Age around 12,000 years ago, and also the Tower of Babel phenomenon, which, in secular terms would simply mean that primitive populations broke off from one another and became geographically, and reproductively, isolated. This alone could account for a large portion of the diversity and require us to view these numbers differently.
I still stand by this statement wd400: “These equations are not ‘truth statements.'” Even if a Christian like Francis Collins accept these data as determining for certain that “man” arose from a population of at least 2,250, he could EASILY be wrong, as others could. This is NOT EXACT science. Just because numbers are being dealt with here does not mean that they constitute some kind of ‘mathematical proof.’ They do not. They have to be understood properly. Their limits in scope have to be taken into account. Dr. Carter makes clear that under certain, perhaps reasonable, assumptions, these conclusions can be interpreted “oppositely” to how they have been interpreted. So, to say the least, leeway in interpretation certainly exists.
Let me point this out. I ran some numbers for a population that 790 of the 800 generations, had a population size of 10,000. The first seven generations were less, and the final three were less. What was the effective population size? 793. Does this make sense?
Not really. Why? Because since we’re dealing with a sum, we can shift the last three generations to the front—the order of the sum (per the equations used) does not make a difference. This would mean that for 10 generations the population size was, on average (not harmonic mean!), 1,000, and then it was 10,000 for 790 generations! Think about this, wd400.
Do you really want to tell me that random genetic drift didn’t take place within a Ne of 10,000? Do you really want to stick to this claim? Think it through. Think about the size of the population, the mutation rate, the number of mutations entering the genomes of that population. Are you telling me that the amount of heterozygosity does NOT reflect a population size of 10,000, but, rather, a population size of 793? Is that what you want to tell me?
IOW, everything in this discussion hinges on using the harmonic mean to establish an effective population size. And, so, the question then arises: how accurate is this assumption? And, a related question arises? Why is this formula used? And, then, one more question: What are the limitations of using this formula?
And, now, let’s remember a little bit of history: in the 90’s, they went looking for “mitochondrial Eve”, and were certain that they would find more than ONE such “Eve.” But that’s not what happened. Why did they believe this. Was it population genetics, or simply that they wanted to prove the Bible wrong? I think I know the answer.
Then they went looking for “Y-Adam,” again convinced that they would find more than ONE such “Adam.” And they thought for sure they would find more than one because they were sure that the Bible was wrong. And what happened? Yes, indeed, only ONE “Y-Adam.”
Now it’s “there couldn’t have been just one Adam and one Eve because the ‘bottleneck’ shows the Ne as being 2,250.” Darwinists have been wrong twice already. I fully suspect that when the final chapter is written, they will turn out to be wrong again—not wrong in the sense of coming up with wrong numbers, but in having interpreted those numbers wrongly.
If Francis Collins wants to say, with Jerry Coyne, that we have “proof,” that’s his business. But I say, let’s wait until more data are available, and more analyses done: then we can see where the science is pointing.
wd400:
Here’s something to think about.
Ne of 2,250. We assume neutral drift and not NS at play. How much time will it take for ONE!!!! mutation to become “fixed” in the population? Answer: 2Ne.
So, 2 x 2,250 x 25yrs/gen = 112,500 yrs!!!
So, just think what the brilliant population geneticists are telling us. That from the time than humans lived in Africa, only ONE!!! allele has become fixed, and only ONE!!!mutation within that allele!!!!
What a great story of macro-evolution this is!!!!
Would you care to respond?
The derrivation of the forumlae for Ne are not straightforward, but are covered in many textbooks. It’s not true, or even possible so far as I can tell, that Wilson and Cann though there would be more that one MRCA mitochondrial DNA (or Y-chom). How would that even work?
PaV,
Ne of 2,250. We assume neutral drift and not NS at play. How much time will it take for ONE!!!! mutation to become “fixed” in the population? Answer: 2Ne.
So, 2 x 2,250 x 25yrs/gen = 112,500 yrs!
This is a common error. It would take ~112,500 years for any given mutation to fix. But there many mutations in each generation. In fact, the fixation rate is equal to the per-individual mutation rate. The brilliant population geneticists are telling us ~100 mutations fix in each generation.
wd400:
Jerry Coyne tells us that 2,250 is bigger than 2.
So, let’s look at an effective population of 2.
Here’s what it looks like: 2/2/2/2/2/2/2/2/2/2/2/2/2/ …….ad infinitum.
Is this what Jerry Coyne is looking for?
Isn’t it obvious that an effective population size of 2 is invisible?
Isn’t it clear the ‘population’ would have died off at some point?
Do you think about these things? Or, are formulas sufficient?
wd400:
But, remember, NS isn’t working. These are “neutral mutations”. What does 100 neutral mutations buy you?
If you respond that the mutations are there at the ready, then you are effectively saying that NS is there at the ready. But you can’t invoke NS. So now what?
wd400:
I’m not asking you to tell me how the formula is derived. It appears to simply be the reciprocal of the reciprocal of the arithmetic mean. So, kind of N=N/N(1/N).
Why is it used here? Can you answer that question. I think I know, so I will be interested in your answer.
It’s not clear to me what you’re getting at here. What are you saying exactly?
I mean the derrivation of the forumula for this effective population size. As I say, it’s not straightforward but you can look it up in most popgen texts.
It’s not clear to me what you’re getting at here. What are you saying exactly?
it’s (a) not true that ‘in the 90?s, they went looking for “mitochondrial Eve”, and were certain that they would find more than ONE such “Eve.”’
(b) not even possible that there could be more than one “eve”
wd400:
Except that “brilliant” shpuld never be used to describe population geneticists as they are far from it.
And their methods do not apply to a Special Creation.
wd400:
This is NOT an error. It is the time required for a neutral mutation to be fixed at a particular location along the length of the genome.
4,500 generations x 100 mutations per generation = Total Mutations over 112,500 years = 4.5 x 10^5.
These are “randomly” distributed along the length of the genome (if we assume NS is turned off, it can even happen in the just 5% of the genome that codes for protein). So, to change a protein, you would need a nucleotide change at a particular location = .05 X 3.0 x 10^9 nucleotides within protein coding regions=1.5 x 10^8 nucleotides.
The probability of such a genome occuring during 112,500 years of “neutral evolution” is …….drum rolls please:
4.5 x 10^5/1.5 x 10^8 = 0.003.
Now the Ne is 2,250. So the odds of such a mutation actually occurring in the population is 2,250/3,000. So there is less than ONE chance of ONE needed mutation to occur in this population over 112,500 years. But, wait a second. It’s supposed to be “neutral”, so it’s likely not a single amino acid will be changed by this mutation—should it even occur.
So, how, exactly, is “evolution” supposed to happen?
That’s starting at 112,500 years ago. So, starting 112,500 years ago, if you push back another 112,500 years, again, less than one chance of a needed mutation occurring.
How do you propose overcoming these dismal statistics?
Michael Behe and Snoke rans some of these kinds of numbers, looking just for a two amino acid substitution, assuming immediate fixation, but also elimination of deleterious mutations, and they came up with staggeringly huge amounts of time required for simple a.a. substitutions to occur; and this only occurs if your population size is enormous.
That study led to “The Edge of Evolution.” Have you read that book?
I’ll have more to say about harmonic means and effective population sizes tomorrow.
I am on a tour in Africa. Our tour guide is from South Africa and like all good tour guides provides interesting tidbits about the local culture etc. He said there is a theory proposed by some South Africans researchers that there was a mass killing off of the human species several thousand years ago and the species was reduced to a small group along the eastern coast of South Africa.
My comment was that he was saying South Africa was/is paradise. I have no ideas if this is bunkum or not but will ask him if he knows of the source of the data. The tour guide is well educated and was a computer programmer before heading off to the bush to live with the animals.
My reaction to this is that science is a Whack a Mole process. Just when one thinks they have killed off one theory another comes out of nowhere that may be the answer.
You said this
So, just think what the brilliant population geneticists are telling us. That from the time than humans lived in Africa, only ONE!!! allele has become fixed,
Which is clearly not the same as “the time required for a neutral mutation to be fixed at a particular location along the length of the genome”.
You now seem to be mistaken in a new way. though it’s hard to follow precisely what youa are trying to calculate. What exactly are you trying to calculate, and who is specifying these “needed” changes?
wd400:
That’s right. It isn’t. But the “time required for a neutral mutation to be fixed at a particular location along the length of the genome” is the only way you can BEGIN to have “evolutionary change.” So what if one million “neutral” mutations are fixed all over the length of the genome. As I’ve already asked you—and you have yet to respond—what, exactly, does this buy you? What value is there?
You admit that you don’t know what I’m trying to calculate, and you admit you don’t know why the changes are “needed”, yet you’re convince, it would appear, that “I’m mistaken in a new way.”
Why am I mistaken? Because what I point to is something that Darwinists/evolutionary biologists refuse to look at?
Here’s an example. I have a genetic defect within my hemoglobin protein coding area that results in defective hemoglobin molecules, which makes me chronically anemic.
Now, let’s say you’re a geneticist, and it’s your goal in life to ‘cure’ this disease. So you look along the length of the HG coding area and see the actual loci (there are two bad a.a.s involved) where these wrongly-coded nucleotides are found. You then devise an entirely new technique which allows you to replace these two or three (possibly four) “bad” nucleotides with the “correct” ones. The person is cured.
Now, using random processes to ‘cure’ the same person requires that, at a minimum, two EXACT locations along the genome must be replace with the “CORRECT” nucleotide.
The probability of replacing the nucleotide with the “correct” nucleotide via random genetic drift is 1/3 x 2,250/3,000 as calculated above. But this is ONLY HALF the problem.
You need TWO mutations. So, for the probability of ONE of getting the “correct” replacement at the first location along the length of the genome, 3,000/2,250 x 3 x 112,500 years will be needed = 450,000 years. Now the FIRST mutation is in place. If you’re lucky, and the FIRST mutation doesn’t change itself again in the intervening 450,000 years (although it is likely that this will happen based on neutral drift —REMEMBER: 100 mutations are fixed EACH generation, and all over the genome), it will take an additional 450,000 years to get the SECOND mutation. And, of course, much more than that if, which is likely, the FIRST mutation disappears.
So,almost ONE MILLION YEARS to change TWO mutations. And, in my case, these two mutations are NEEDED. You don’t mind if I do the specifying, do you?
So, tell me, the time it took to go from a ‘chimp’ to a ‘human’, what is it? 6 million years? Per my calculation, via random genetic drift, this “buys” you 13 a.a.s in places where the ‘chimp’ to ‘human’ transition happens.
Just out of curiosity: are there more than 13 a.a. differences between chimps and humans?
The answer is: Of course! Don’t you think, then, that there’s something wrong in presenting this supposed method as a way of bringing about “macro-evolution”?
Progress, you’ve admited to getting something wrong 🙂
Because the equations following your sentences don’t appear to be related in any obvious way. You get yourself in another mess in this post which I don’t have time to umtangle.
If you wan to know what’s the proability that pre-sepcified mutation will fix in a population by dirft in less that a million years then the answer is close enough to zero to make no difference. After all, chimps and humans have been evolving apart for 6 million years (=12 million years of evolution) and we have very few fixed differences.
But why is that important? No one things drift is responisble for adaptation. Using neutral models to explain demography of genomic patterns doens’t preclude us from using selective models to explain other parts of biology. As I’ve said from the start, there is a lot of evidence for the fact natural selection has been at work in our genome.
Well, your calculations are wrong.
Let’s look at it per gene, as the numbers are easier to follow, and you have the exonic portion of DNA wrong in your ealier comments. The average polypeptide is 400 amino acids long = 1200 nt.
Using back-of-an-envelope numbers, the per nucleotide mutation rate is ~2.2e-8 and ~25% of mutations are synonymous. Over 6 million years, each lineage would have 240 000 25yr generations so we’d expect
1200 nt * mu = 2.2e-8 * 240000 gen * 2 lineages ~ 13 substitutions per protein.
13 per protein rather than 13 per genome.
In fact, the observed number is smaller that the one we just calculated, due to the effect of purifying selection. The rate at which non-sysnomous mutation fix is ~1/5 the rate at which synomous ones fix (and 13/5 is 2.6 which is about the average number of amino acid differnce between human and chimp proteins). So the neutral rate would generate more differences than we observe, the fact we don’t see so many is evidence for the operation of selction.
When did I do that? I said we can use a neutral methods to infer demographic histories. That doesn’t mean neutral theory explains all of “macro-evolution”, what ever that term means to you.
wd400:
I’ve asked you why the ‘harmonic mean’ was used in calculating Ne. You told me that I should look at how it is derived.
I’ve done that. Now I’m reporting back.
First of all, we’re dealing with the theory of random genetic drift that is attributed to Sewall Wright and R.A. Fisher. It’s been around since the 30’s and 40’s.
It is based on the “infinite allele” model. This model assumes an infinite population that produces an infinite number of alleles, that is then subdivided into N sub-populations, each of which itself produces an ‘infinite’ number of alleles. So this is quite an ‘idealized’ model.
Therefore, when implementing it, one has to move from the ‘ideal’ population model and actual populations. Corrections, therefore, must be made in applying the model; one of these has to do with population size, and Ne, effective population arises within the context of making this correction.
Any quotes I include in the following come from a Nature’s Review article by Armando Caballero, published in Heredity in 1994.
“Under the simple conditions of the idealized population, sampling of gametes is binomial and the variance of the change in gene frequency is:
?²(Δ q) =q(1-q)/2N,
where q is the allele frequency of a gene in the infinite base population. The coefficient of inbreeding at generation t, the probability that two gametes which unite to produce a zygote in generation t carry identical by descent copies of a gene (Wright, 1922; Malecot, 1948), is:
F_t = 1/2N + (1-1/2N)F_t-1,
where the first term denotes identity by descent from copies of a gene of an individual in generation t-1 and the second, that from copies of a gene of an individual in previous genrations. The rateof incresae in inbreeding per generation is thus:
Δ F = 1/2N
where Δ F =F_t-F_t-1/1-F_t-1.
The observable consequence of this increase in inbreeding is a reduction in the expected heterozygosity (H) each generation,
λ=H_t/H_t-1 = 1-ΔF ……… (3),
or, relativ to that in the base population,
H_t/H_t-1 = 1 – F_t = (1-ΔF)^t. …………..(4)
[(N.B. the 1-F_t is from a straight substitution of the equation above (3) directly into (3). And, since, this equality is true for EACH generation, gen 0 to gen t, then the power of “t” is arrived at) PaV]
. . .”
Caballero gives a few more equations that won’t be interesting us, and then says:
“It is obvious that real populations are very unlikely to meet the conditions of the idealized population defined above and, therefore, the number of breeding individuals does not describe appropriately the effects of inbreeding and gene frequency drift in most practical situations. The concept of effective population size (Ne) was introduced by Sewall Wright (1931, 1938, 1939) to overcome this problem and has been developed subsequently by others, mainly James F. Crow and coworkers (Crow & Kimura, 1970, pp. 345-364; Crow & Denniston, 1988).”
How do we get effective population size, Ne?
“If the variance of change in gene frequency or the rate of increase in inbreeding are known, because the genotypes can be distinguished and hence the genotypic fequencies estimated or because pedigrees are available, the effective population size can be estimate or computed directly from the expressions above. For example, if we can trace an observable quantity such as the heterozygosity so that we know its rate of decay (H_t/H_t-1), we can use eqns (2) and (3) to estimate the asymptotic N_e. . . .
When information on genotypic frequencies or pedigrees is not available, effective size can still be predicted under certain circumstances (in which one or more assumptions of the idealized population are removed) when demographic data such as census numbers and variances and covariances of the number of progeny per parent are available. Effective size can be derived following a sampling drift approach or an inbreeding approach when the matter of interest is in the gene frequency drift or the increase in homozygosity, respectively (Crow 1954).”
So, just as I suspected, and as I stated above, one either had the numbers and information, or one “backs into” N_e. When you have to estimate it without available information, then you have to remove “one of more assumptions of the idealized population). This is exactly where the HARMONIC MEAN comes in.
We move down in the paper:
“4. Variable population size over generations
In the idealized population the number of breeding individuals (N) is constant over generations. Let us consider a situation where the population size varies over generations, with size N_i in generation i. From eqns (3) and (4), the expected heterozygosity in generations t relative to that in the base population is H_t/H_t-1=Πi=1-t (1-1/2N_i). This can be equated to the relative heterozygosity in the idealized population (eqns (2) and (4), replacing N by N_e, i.e., (1-1/2N_e)^t. When population sizes are large and t much smaller than any of these, this latter equality can be approximated by
1-Σ_i (1/2N_i)≈ 1-t/2N_e, from where:
1/N_e≈ 1/t Σ_i [1/N_i]
(PaV: summations are from i=1 to i= t)
(Wright, 1938; Crow & Kimura, 1970pp. 109-110),
i.e., using the harmonic rather than the geometric mean.”
So, there you have it: the derivation and the reason for using the harmonic mean.
But, we’re not through yet.
I’ve argued here, over and over again, that it is plain silly to say that a growing population represents a “bottleneck.”
Well, here’s what Caballero has to say to us:
“Because N_e is a harmonic mean, two important points similar to those explained for eqn (7) appear. [N.B., eqn (7) deals with a different assumption of the idealized population, and its only relevance here is that as in the case of using the harmonic mean, caution must be exercised when applying this deviation from the idealized model] Firstly, the maximal N_e, given a total Σ_i N_i, is achieved with constant population size over generations. Secondly, N_e is most strongly affected by periods of reduced population size. In other words, if a bottleneck occurs, causing an increase in inbreeding, this is not restored by a later expansion of the population size. . . .
As was mentioned before, genetic drift begins one generation (if selfing is allowed) or two (if not) earlier than inbreeding. If population size varies over time, for a given generation, genetic drift depends on the number of individuals in that generation whereas inbreeding depends on the number of their parents (if selfing is allowed) or their grandparents (if not).”
So, when I describe a population that grows from 2 individuals to 28,000 individuals over a 7 or 8 generation time frame, this means that only (depending on the mutation rate) 1,400 to 1,600 mutations will have been fixed. Then after that, it’s “harmonic mean” will be that of its maximum value since it will have a “constant population size” for the next 9,900 generations.
To summarize:
(1) I was right about scientists having to “back into” the N_e when actual information is lacking.
(2) I was right about a ‘constant’ population size over many generations.
(3) This means I was also correct in saying that an “effective population size” of 2,250, or even, 28,000 can be reached in a very few number of generations, and is, therefore, blind to the method being employed.
(4) Just to underline all of this, from an earlier post, an “effective population size” of 2 looks like this (generation numbers as well as generations, separated by slash marks:
2/2/2/2/2/2/2/2/2/2/ …………………2/2/2/2/2/2/2/ …………………..2/2/2/2/2/2/ …………..
(2) Nope. Your own source, which you pasted here, says “Secondly, N_e is most strongly affected by periods of reduced population size. In other words, if a bottleneck occurs, causing an increase in inbreeding, this is not restored by a later expansion of the population size.”
(3) Nope. See above.
(4) Sure. Why is this important?
Actually, can you succinty point out what you are trying to do with any of this? I’ll remind you that orignal paper finds now evidence of a severly small population in more than a millon years, the newer one extend back less far but still no sign of a severely small population. We know that Ne is “strongly affected by periods of reduced population size”, so if there was a bottle beck prior to these evens it would still show up these studies. It hasn’t.
You might be able to create some post hoc reason that saves a literal Adam and Eve, just like it’s possible to say the world was invented yesterday complete with memories, but it’s clear genetic evidence doesn’t support such a couple.
wd400:
The ONLY mistake I made was in saying “a particular place along the genome” instead of “a specified place along the genome.” For some reason you EBs like “pre-specified.” I think it only confuses things. Why not just use “specified”?
Yes, the “exonic portion” is probably about 3%; but, as usual, I give the EBs a break and used a higher percentage. And for this, you tell me I got it wrong.
My calculations used 4,500 generations. Sticking with only one lineage, since the only reason to include 2 lineages is if, as you stay further on, if you want to study when they separated, then we get:
1200 nt * 2.2 * 10^-8 *4,500 = .122 which, though different, means that during those 4,500 generations it is likely that no mutation occurred in any of the protein coding area.
Using your same numbers, but looking at just ONE lineage, there are about 6 mutations per exon.
That’s 6 nucleotides within an exon of 1200 exons. Now what percentage of the average exon is conserved? We’re talking here about NGD, so are we not talking about “neutral” substitutions?
But you go on to note that non-synonymous mutations “fix” at 1/5 the rate of synonymous mutations. So that means, on average, 6/5, or, ONE nucleotide per exon; or, at most, ONE a.a. difference per exon.
Now this is with purifying selection turned on.
I guess this means that if you compare two exons, one from a chimp and a corresponding one from a human, out of the 1400 nucleotides only ONE nucleotide is different. And this is what converts a chimp into a human. Is this what you want me to believe?
But, just a little bit more. You’ve made your calculation using 2 lineages. The reason for that, I presume, is that you’re considering the NGD that takes place within the chimp population. So this means that the chimp lineage changed from what it was like 6 million years prior by about ONE a.a., while the human lineage changed from what the chimp lineage was like 6 million years prior.
So if you want to say that NGD is responsible for changing chimps into humans, then, in the same amount of time (you’ve assumed this) the chimps, having undergone an equal amount of change, nevertheless, still remain chimps! Why haven’t they changed into something different?
If the numbers impress Darwinists/EBs to have confidence in macro-evolution, wherein a chimp, little bit by little bit, changes into a human, then why didn’t chimps change, little bit by little bit, into something else more similar to themselves, not as profoundly different as mankind? IOW, is there a chimp species that shows itself diverging from another chimp species less than 6 million years ago?
I don’t know. I’m asking the question. But if there isn’t, then this absence appears to be rather peculiar.
Another curiousity. Is the effect of purifying selection that of reducing the mutation rate of non-synonomous mutations to one-fifth that of synonomous mutations determined mathematically, stemming from some kind of first principles; or do you just simply back yourself into it by noticing the a.a. differences between humans and chimps and then calculating the numbers?
Again, what mechanism, exactly, are you proposing for macro-evolution to take place. And, again, if you leave Darwin behind, saying that the EBs have moved on from his original theory, then surely science requires you to propose some new mechanism. And, of course, science would further require you to propose a sensible, logical mechanism.
Is there one you would now propose?
wd400:
Believe it or not, I can actually read. You’ll notice I included the quote you’ve posted. But I didn’t underline it. There are two caveats: one about ‘bottlenecks’ and one about ‘constant population size.’ You choose to focus on the ‘bottleneck’ and I choose to focus on the “constant population size.’
Please explain to me how going from 2 to 50 to 500 to 2,000 census population, and then remaining at N = 2,250 for the next hundred generations, represents a ‘bottleneck’. In what way?
One reason is that Jerry Coyne said that 2,250 is greater than 2. Does this mean he thinks that effective population sizes of 2 can actually exist?
Second reason: it is silly to think that one can look at what came before a “bottleneck”. I’ve already shown this a number of times. You seem not to want to accept this reality.
Clear genetic evidence? Really? What’s so ‘clear’ about it? As I’ve stated over, and over, and over again, you can’t see what’s ‘in front’ of a “bottleneck”. The only reason that they talk about a population size of 10,000 going back in time, is because of the Out of Africa theory. So, you use one population, the African one, as the ancestral population, and then you compare the European populations with that of the African one. When you compare Europeans, you go back, what, was it 67,000 years. That’s where the “bottleneck” supposedly occurred, based on heterozygosity and assuming NGD; and, meantime you’ve backed into a N_e. Isn’t that how the computer simulation is done?
But the point is is that this doesn’t allow you to look back past the 67,000 year mark using the European population data alone.
If, in the original paper, they said something like the effective population of the African population is 10,000 going all the way back in time, why, then wasn’t it 9,350?
Probably because that is their best guess for N_e. Then you use that to figure out some time to a “bottleneck” based on the heterozygosity of the African populations. And what comes before the 10,000 at it’s earliest? I’m sure they have no idea. It’s guesswork. And, so, the same is true of the European data set.
Bottlenecks end in blindspots, not actual population sizes. Unless, of course, you’ve actually done some kind of field study. Using an infinite allele model–as does NGD—I don’t see any other alternative understanding.
Believe it or not, I can actually read. You’ll notice I included the quote you’ve posted. But I didn’t underline it. There are two caveats: one about ‘bottlenecks’ and one about ‘constant population size.’ You choose to focus on the ‘bottleneck’ and I choose to focus on the “constant population size.’
They aren’t caveats, they are consequences of the fact the harmonic mean gives us the value of Ne under these circumstances. Ad you can’t ‘choose to focus’ or one thing or the other, they’re both true. With the harmonic mean long-term stable populations have higher Ne, and populations recovering from a period of very low populatin retain low Ne for a long time.
Because there is much less diversity in such a population than one that has been at 2,250 for ever. As the text you quoted says, it takes a long time for the population to get back towards the equilibrium
This is extradondairy. No, this is not how the study was done. Inf fact, the Li and Durban paper uses a single genome to infer past population sizes. These methods use the distrbutions of times-to-coalescnce of blocks of chromosomes to to inder past populatin sizes. When effective population size is small you get many such coalesences quickyl, when it’s large that are more spaced out.
It should be obvious from this that bottlenecks are not ‘blindspots’ or barriers through which such methods can’t see. For wthat it’s worth an Ne of 10,000 is most commonly used for humanity as it is calculated from observed genetic diversity in modern populations.
And that, ultimately, is the problem. You’ve laboured in this entire thread, attacking your own misunderstanding of how these method work,without, it seems, considering the idea that specialists in population genetics know what they are talking about and don’t extend their estimates back beyond ‘blindspots’.
wd400:
This is just “preachy”. It’s like you’re in a classroom teaching some young 19-year old. I’m sure they’ll accept your answers. I don’t. You’ll have to do better than you’ve done so far.
I’m sure you really think this. And I’m sure you think this because it’s the prevailing dogma. But I’m looking for answers, not just dogma.
Let me illustrate what I mean.
You have made no attempt whatsoever to try and understand the objections I have made in terms of the model being used. You’re content to give me bromides.
The model that is in play is the “infinite allele” model, is it not? This model says that you begin with an “infinite population” with EACH generation itself producing an INFINITE number of “alleles.” The next generation is randomly selected from this host of “infinite alleles.”
Now, where on earth will you find an “infinite sized population” that each generation produces an “infinite” number of alleles? Nowhere. (And, yes, I know about permutations of a genome that is billions of nucleotides long is quasi “infinite”, etc. I understand all that. So no lectures, please) So, when dealing with actual populations, but, in particular, populations that fluctuate over time, an “effective population” calculation is used to correct for the idealized assumptions.
However, as far as I can see, you fail to engage the implications of the model. That is, the ENTIRE CONCERN is that when the population size is reduced, the notion of an infinite number of individuals producing an infinite number of alleles is thrown way off. Another way of looking at it is to simply say that when there is a “bottleneck”, a lot of diversity is lost because the diversity ‘exists’ over the entire population. Once it is lost, it will take a long time to recover it. In fact, depending on the lineage, and how far back in time it goes, you may never fully recover it.
Now that is all you’ve been saying. But, that’s not the end of the story. For you, however, that is the end of the story. And when I get you to think it through more carefully, I get one lecture after another. Yes, indeed, the Ivory Tower is quite high.
I will now point out how you are completely unresponsive to what I’m trying to point out.
Answer this simple question: which of the two populations below has suffered from a “bottleneck”?
(1) Population A: here is part of its history (population sizes of each generation separated by slashes):
100/200/600/2,000/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250 and so on for another 5,000 generations.
(2) Population B: here is part of its history (slashes again separate generation size):
9,450/9,200/9,760/8,760/3,700/2,700/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250/2,250 and so on for 5,000 generations.
I won’t wait for your answer, because I don’t think you’ll want to answer. So I’ll just avoid all the gamesmanship.
According to you, both of these should be considered “bottlenecks.” Right?
And what does this mean? It means what I’ve been saying now for over a week. It’s saying that if there is a “bottleneck” then you have no idea whether the population size of the population before the “bottleneck” was ten times greater or ten times smaller than the calculated N_e. If you a before and after picture, and you can’t tell whether something gets ten times bigger or ten times smaller, then I suggest you must be ‘blind’.
Are you willing to admit that my interpretation is the correct one?
I don’t see what you think is so extraordinary.
Let me tell you what I see that is extraordinary:
I am not talking about Li and Durban. I’m talking about Sheehan’s paper and they use more than one genome. But this is not big thing, since both are basically using a newest variation of the “coalescent” method.
And what are they doing with the method? They’re going back in time using some rule for RGD, instead of going forward in time. And what is it they’re looking at which is going to “coalesce”? They’re simply taking some consensus genome for the European population and another consensus one from the African and using some form of simulated Markov method until the present day chromosome length “coalesces” to the “original” allele.
Here’s what they say in their Discussion section:
Applying our method to a 2 Mb intergenic region of chromosome 1 from ?ve Europeans and ?ve Africans, sequenced as part of the 1000 Genomes Project, and using a per-generation mutation rate of µ = 1.25×10?8 per site, we have inferred a severe (out-of-Africa) bottleneck in Europeans that began around 117 kya, with a drop in the e?ective population size by a factor of 12. In contrast, we have observed a much more mild population size decrease in the African population. We remark that our estimate of the timing of the bottleneck may not be very accurate, since we used only 16 discretization intervals and 7 free population size parameters. Furthermore, all of our inferred times and population sizes would be smaller by a factor of two if we had used µ = 2.5 × 10?8.
What is the difference between “inferring” these numbers and “backing into them”?
So, it’s a bit extraordinary that you get so worked up by what I stated.
Did you notice it wasn’t “one” genome, but five; and it wasn’t just one population, but both African and Central European. And the factor of 12 they’re talking about is a drop from their calculated N_e for Africans at the time of split of 28,000, and the 2,250 they calculated as the N_e for the Europeans.
Isn’t it quite obvious that based on Sheehan’s paper, from which Coyne (remember him? That’s how this all got started) then said that 2,250 is greater than 2, implying that Europeans are directly descended from Adam and Eve, rather than what is quite obvious from Sheehan’s paper, that the Europeans are descended from the African lineage.
So, we go back to Africa, and then we go back in time, and then we estimate an effective population size of 10,000, and then we say, “Obviously we’re not descended from Adam and Eve, but some chimp lineage that numbered around 10,000.”
This isn’t science. This is assuming evolutionary theory to be true, and then interpreting everything accordingly, and then saying that this is all demonstrable.
The fact of the matter is we don’t know enough, and probably will never know enough. But when scientists want to trumpet “effective population sizes” as evidence that there was never an Adam and Eve, well, this sounds to me much like what it must sound like to you when a true Creationist says that the world was created in six days.
It has been against this improper extension of science that I’ve been railing against.
The infinite allele model does not include an infiniate population size. In fact, the most famout eqn in the paper is
F = 1 /[ 4Ne.u + 1]
I think(?) you are talking about the idealised Wright-Fisher model. The infinite thing in an infinite sites model is the number of possible alleles (i.e. each mutation is making a new allele).
You yourself described the derrivation of why both populatins have genetic reduced diversity, so I don’t why you keep on going on about the semantics of ‘bottle necks’. The thing I think you haven’t quite grasped is the difference between an instantaneous value for Ne (which could be arrived at from many histories) and the histroical reconstruction of Ne over many time periods that these coalescent methods produce. That’s why these graphs extend out past the OOA bottlenecks in non-African populations.
Anyway. It’s become increasingly clear you are so wedded to your ideas that you want give them up (do you at least admit no one though there would be multiple mtEves?). So I think I’m going to find something better to do than this.
wd400:
This is from Caballero’s 1994 article:
The simplest possible conditions under which the
dispersive process can be studied are met in the
Wright—Fisher idealized population (Fisher, 1930; Wright, 1931). This consists of an infinite, randomly mated base population subdivided into infinitely many subpopulations, each with a constant number, N, of breeding individuals per generation
Yes, the “subpopulation” is not infinite (I’m sure the infinite population is being used to justify some kind of mathematical trick). And, yes, it is the Wright-Fisher model. I stated that somewhere along the line. And, yes, that’s not the coalescent theory, but coalescent theory is built upon the foundation of the neutral theory. And, yes, as I stated twice already, each generation produces an infinite number of alleles.
The thing I think you haven’t quite grasped is the difference between an instantaneous value for Ne (which could be arrived at from many histories) and the histroical reconstruction of Ne over many time periods that these coalescent methods produce. That’s why these graphs extend out past the OOA bottlenecks in non-African populations.
It seems to me that “coalescence” takes place when you run out of ‘heterozyogisity.’ You end up with one allele, or one form, etc. That’s where you’re going to determine where the MRCA is. This number obviously depends on the methodology employed, and it is not always going to be the same estimated time. And, of course, these methods suffer— as all methods involving molecular biology do, like molecular clocks and phylogenies—with inconsistencies. Nevertheless, some helpful information is gained, and it is certainly gained in as scientific a manner as is available.
Again, I just notice the limitations of such methods, and we’re wrong to not notice them.
(do you at least admit no one though there would be multiple mtEves?)
Can you rephrase this? There may be a word missing.
As to the discussion, I would agree that it has been more than thoroughly hashed out.
You said this.
Can you admit you got this wrong?
PaV might not be wrong at all—but you might be, wd400.
From what I’ve read, there seems to have been a reaction by paleoanthropologists in the 1990s against the 1987 Mitochondrial Eve theory.
While Darwinists claimed that ME was represented by many women, Paleoanthropologists observed genetic traits in Homo erectus fossils simultaneously in various parts of the world—arguably MEs in Asia, Africa, and Europe (Neanderthals).
Interestingly, there actually *three* primary mitochondrial lineages that are observed in the world today (M, N, R) that could nicely correspond with the three fertile mothers on Noah’s arc, and also explain the genetic bottleneck as due to a global flood.
For anyone’s interest, Dr. Robert Carter speaks on mitochondrial DNA and other genetic topics starting at 30:30) at http://www.youtube.com/watch?v.....38;t=9m40s.
-Q
wd400:
From what I know, aren’t you about 30? That means you were what, ten years old when all this was going on, while I was in my forties. Do you want me to deny reality? Is that what you’re asking me?
It was in the papers. It was a topic of discussion. I remember it vividly. I waited expectantly for their results exactly because if there were multiple origins of “Eve” this would prove troubling. And then they were surprised when it turned out that there was only ‘one’ Eve. I remember all of this very well. We’re not in a communist state, yet; so I’m in no way going to deny reality.
Unless you’re older than forty, I’m not going to accept a word you say. Darwinists, like Communists, rewrite history to please themselves. Don’t drink the Kool-Aid, wd400.
Now, shifting back to our discussion: I hammered away at making the point that science cannot see clearly enough beyond these “bottlenecks.” However, there’s another way of looking at all of this.
When we look at Genesis, Cain, after killing Abel, is sent off. He’s afraid that he will be killed; so he is given a special ‘mark.’ It sure sounds like we’re dealing here with other human-like primates.
Let’s remember that what gives us freedom, and the use of reason, is our consciousness. Without this, we are mere animals. Think of someone who sleepwalks: they move around, talk with people, and do other things; but they’re not at all self-aware of what they are doing. It is consciousness that elevates us above all the other animals.
It is entirely possible that the account of man’s creation in the second chapter of Genesis has to do with God infusing consciousness into human-like primates.
If this is true, then genetically, these “persons”—human-like primates now having “consciousness” (likely changed in some ways)—would be linked to the genetic history of the group from which they were formed.
The Bible, in my estimation as a Catholic, is not a history book at all times (it is quite a good history book at other times), and this applies to the Genesis accounts of Creation. It says there that God formed man out of the clay. But, of course, in Chapter 1 it just finished saying that God made men and women and told them to fruitful and multiply. So there is really no clear and unequivocal understanding here, and so caution as to how we understand all of this is in order.
But, I invite your comments about the genetic history perspective I’ve presented.
BTW, this is why I said earlier that I don’t see linkages of humankind (as we now know it) to chimps and such as a problem. Now, do I consider this to be “common descent”? I don’t think so. I think it is very likely that God intervened in some manner. For example, in order to accomodate “consciousness” was a larger cerebral cortex needed? Etc.
I don’t know that we will ever have a full story of this. As I see it, neither religion nor science, neither Darwinism nor Intelligent Design, will ever know enough as to make a definitive conclusion about all of this. We’re all called to understand this as best we can, and in the best way possible.
Anyway, your comments.
Thanks, Querius, for your comments.
I remember all of this happening in the early 90’s, but it could have easily been the late 80’s too.
Of course, then it was off to “Y-Adam.” And another surprise.
wd400:
We’ve lived through Darwinists pounding away at IDists, night and day, for years and years, that the presence of so much “junk-DNA” is proof that Darwinism, and not ID, was correct. Then, when they could do this no longer in the face of so much conflicting evidence, they now, quite conveniently, just say: “Oh, when did we ever say that?”
This sounds very much like your: “Oh, they never expected there to be just ONE “mitochondrial Eve.”
When they asked Nixon how history would view him, he replied: “It depends on who the historians are.”
It’s not possible for their to be more than one mitochondrial eve. How could that possibly work? Since Cann and Wilson and other geneticists in the 1980s were not idiots I think we can safely rule out the claim that they were expected to find multiple eves, and put all this “Darwinists are like communists,re-writing history” stuff aside.
I guess you are confused by the difference btween multi-regionalism and Out of Africa. But neither of those schools thought there would be mulitple eves (and indeed, even in out of africa there are regionally unique mitochondrial lineages)
So, you were wrong again. I won’t hold my breath waiting for an apology about all this childishness comparing evolutionary biology to communnism and Nixon…
(Oh, and it hardly matters, but the best evidence still points to most of the genome being junk, and this is indeed evidence for that fact out genomeis the product of evolution.)
PaV:
A woman alive today will be a future mitochondrial eve. Every woman alive today is a mitochondrial lineage. Each generation from now, there will be women who either don’t have children, or have sons but no daughters. Thus, each generation from now, there will be fewer and fewer women of today that can claim any mtdna descendants. Eventually it will be just one woman.
So the question simply was, how far back do we have to go before there is a single woman who is the mdna ancestor of all women today? (Note that the answer to who’s Mito Eve is irrelevant to the question of human origins. It’s also not a fixed individual. The mito eve of humans a hundred years from now might be someone different.)
If you go back to a point where there are still several mito lineages from which mdna today originates, than, by definition, you haven’t gone back far enough. So not only is it not true that several mito eves were expected, it doesn’t even make any sense. It’s nonsensical. What would it even mean?
Here’s an article from Science mag 1987:
“The Unmasking of Mitochondrial Eve”:
“Because mitochondria pass from generation to generation only through the female line… the phylogenies inferred from mtDNA data essentially trace maternal inheritance: ultimately, a single female is reached at the root of the tree, hence the reference to Eve.”
http://www.sciencemag.org/cont.....24.extract
It’s the same for Y-Adam. At some point in the past there is a man who’s the Y-chromosome ancestor of all men today. It’s not much of a prediction that such a man exists, it’s what HAS to happen, for the same reason a mito Eve must exist.
In Dawkins’ “River Out of Even” (1995) he predicts that the Y-Adam will be a man who probably lived long after mito Eve. This was (IIRC) about 5 years before the results of the first Y-Adam study were announced.
http://news.sciencemag.org/200.....osome-adam
If you can find any articles that predicted otherwise, I’d really love to see them – it would be fascinating to see what on earth they were talking about.
wd400:
You still have not answered how old you are.
And I’m not going to. My own experience is irrelevant to the fact that speaking of mulitiple mitchondrial eves makes not sense. To suggest (without evidence, I might add) that genetcists expected to find multiple eves is very strange indeed.
goodusername:
Thanks for the link. Here is what is in the third column of the 1987 Science paper:
Would you like to rephrase your remarks concerning this, wd400? You see, Communism prevails.
And goodusername, what I was stating was right there in the article. So I won’t have to point anything out to you.
PaV,
It appears that WD400 was right in #89, this is confusion regarding the multi regional theory vs the out-of-africa theory.
No one – including the proponents of the multiregional theory – were saying that there wouldn’t be a single mito Eve at some point going back. As explained, there HAS to be one due to the facts of how mtdna is passed on and that we’re a sexually reproducing species!
Many of the proponents of the out-of-Africa theory did make much of the results of the study. Not because there IS a mito Eve (everyone knew that there would be one), it’s that she lived perhaps more recently than some predicted, and came from the very region where the out-of-Africa proponents were suggesting that modern humans originated from. It’s perhaps a point in favor of the out-of-Africa theory, but I’d say a small one, at best.
Had the study said that mito Eve from from eastern Asia 400k years ago, it would perhaps be a point in favor of the multiregional theory, but again, a small one. It’s pretty random who mito Eve is going to be, and as explained, it’s a moving target. A thousand years from now, mito Eve may indeed be someone from Asia. Even as a proponent of the out-of-africa theory myself, I think much too much was made of this study. This is why I said it’s irrelevant to the question of human origins. As explained, someone today will someday be a “mito eve”, but it doesn’t mean that this is the start of a new species or anything.
It can be any woman today that has, or will have, daughters. (If you meant something else by the question I’m afraid I missed it.)
Hi PaV and wd400,
Professor Felsenstein was kind enough to respond to a query of mine regarding Adam and Eve, over at http://theskepticalzone.com/wp/?p=4200 . See especially
http://theskepticalzone.com/wp.....ment-43066 ,
http://theskepticalzone.com/wp.....ment-43193 and
http://theskepticalzone.com/wp.....ment-43375 . You might find his remarks helpful. Cheers.
Would you like to rephrase your remarks concerning this, wd400?
No. It’s not possible for there to be more than one mtEve and multi-regionalists did not expect there to be more than one (rather, they thought mtEve would be much older than the OOA school did)
You comments to goodusername suggest a lack of understanding about who mtEve is. The title can obviously change hands, and you don’t wars or famine or floods for other lineages to die out. In fact, there must have been an molder tEve for the population in which “our” mtEve lived!
I wouldn’t listen to Joe – he’s an evolutionary biologist and and the son of communists! You know who those people re-write history 🙂
LOL PaV,
Don’t embarrass wd400 regarding his age.
Speaking of communists, many people can’t recognize their indoctrination. History is a great place to start. For example, according to a friend of mine who emigrated from the Soviet Union, Russia did not sell Alaska but leased it to the U.S.for 99 years, for which they were never paid. Also, that Abraham Lincoln imported large numbers of Irish to help him win the Civil War. Choose your historian . . .
When wd400 claims
This is because his imagination is limited to what he reads in his text books.
From Homo erectus in each region, Africa, Asia, and Europe, emerged a female most recent common ancestor (MRCA) to Homo sapiens, each with unique mtDNA. The emergence was independent and at a similar, though not identical point in time. These three independent Eves were genetically similar, although the European and Asian Eves suffered a recent genetic bottle neck while the African Eve did not.
It’s easy if you try.
-Q
From Homo erectus in each region, Africa, Asia, and Europe, emerged a female most recent common ancestor (MRCA) to Homo sapiens, each with unique mtDNA. The emergence was independent and at a similar, though not identical point in time. These three independent Eves were genetically similar, although the European and Asian Eves suffered a recent genetic bottle neck while the African Eve did not.
Where did African, Asian and European Eve’s get their mtDNA from?
Their respective mothers.
And where did Pan troglodytes mtDNA come from? 😉
-Q
whoe in turn inherited their DNA from their mothers, and back to…. the inevetiable single common ancestor of mtDNA: the one and only mitochondrial eve.
Chimps have their own mtEve, as does every species with strict matrilineal inheitence of mtDNA.
goodusername:
wd400:
So, wd400, you’re suggesting that the “African, Asian and European Eves all received their mtDNA from ONE ancestral “Eve”.
goodusername, you say I’m wrong. wd400 says I’m wrong. Both of you tell me that what I read and heard in the early 90’s, when all of this was hitting the popular press, is just my imagination. (I suspect that in the back of your mind, wd400, you’re thinking that I’m just not smart enough to follow this sort of stuff. This thought gives you comfort, I suppose)
So, now, wd400, let me point out where you seem to be going wrong when denying my thesis. If, indeed, as you are implying, the African Homo erectus, and the Asian Homo erectus and the European Homo erectus all received their mtDNA from some ancestral Homo erectus, then the transition from Homo erectus to Homo sapiens had to have taken place—or, at the very least, could have taken place [after all, we wouldn’t know for sure until the DNA evidence was in]—in THREE different locations, meaning that “man” (human beings–intelligent, free, human beings) arose in three different locations: the VERY thesis I said was “in the air” at the time.
[Let me just point out that in the early 90’s I hadn’t read a single population genetics book. Didn’t know the field existed. Wouldn’t have known the’Hardy-Weinberg Equation’ if I saw it in glowing letters.
So, I’m simply telling you what was being reported in the press. Everyone was just waiting for ‘humanity’ to have arisen in more than one spot. You know, they wanted the notion of the “Garden of Eden” to be smashed.
Now, most reporters have very little understanding of the subjects they’re writing about, and make mistakes in reporting all the time. So it is entirely possible that they were simply confused about what the experts were telling them. But that is how it was reported. And it sure sounded like there were a lot of different scientific views of all this.]
I take it that you’re not going to aver that “Adam and Eve” were Homo erecti.
Would you now like to backtrack a little?
This is all for right now.
P.S. vjtorley: did see your post, and did look at Felsenstein’s response. I guess there is no “scientific theory” of the soul. Can’t argue that one. Or can we? Hmmmm.
Would you now like to backtrack a little?
no, it remains true that it is not possible for there to be more than one mtEve.
I don’t what the press was reporting, or what you were reading. But the multiregional position did not suggest multiple origins for modern humans. Rather, they thought gene-flow among the different continents (the ‘lattice model’) pulled the whole species along from H. erectus to H. sapiens whle retaining some regional variants.
Here’s Wolpoff himself making this point <a href="dx.doi.org/10.1002/(SICI)1096-8644(200005)112:13.0.CO;2-K”>Multiregional, not multiple origins.
I don’t know if the press got it wrong, but it’s not true that when ‘they’ went looking for “mitochondrial Eve”, ‘they’ “were certain that they would find more than ONE such ‘Eve’.”
Whoops, clickable link
wd400,
Bingo!
So as we move from Homo erectus to Homo sapiens, I’m suggesting the possibility that this step happened independently in three geographic regions, hence you now have a scenario for three different mtDNA sources with different mutation histories for Homo sapiens. If you imagine a micro version of parallel evolution, you’ve got the concept.
-Q
So as we move from Homo erectus to Homo sapiens, I’m suggesting the possibility that this step happened independently in three geographic regions, hence you now have a scenario for three different mtDNA sources with different mutation histories for Homo sapiens
But all three regions had to inherit their own mtDNA from somwhere. Trace the lineages of the three “eves” back and they have to join up in the common ancestor to all human mtDNA…. the one the only mitochondrial eve.
wd400,
That’s the heart of the issue. I’m suggesting that under similar environmental pressures and presumed mutation opportunities, it’s not impossible for more than one H. Sapiens mitochondrial Eve to emerge from H. erectus. In fact, it’s likely that there were many other “candidates” that didn’t survive due to pathogens, predation, infant mortality, etc. and not just one, unless you’re proposing divine intervention for a single, very lucky female. 😉
The apparent lack of other mt Eves is also supportive of a severe genetic bottleneck from a catastrophic event or perhaps a disease that wiped out all but a few individuals.
-Q
That’s the heart of the issue. I’m suggesting that under similar environmental pressures and presumed mutation opportunities, it’s not impossible for more than one H. Sapiens mitochondrial Eve to emerge from H. erectus
And you are wrong. The different ‘eves’ you imagine had the themselves inherit mtDNA. Trace thier histories back and you woul arrive at the shared common ancestor all modern human mtDNA – mitochondrial eve.
In fact, it’s likely that there were many other “candidates” that didn’t survive due to pathogens, predation, infant mortality, etc. and not just one, unless you’re proposing divine intervention for a single, very lucky female.
Ever single women that has every lived, including those alive today, is a candidate to be a future mtEve.
The apparent lack of other mt Eves is also supportive of a severe genetic bottleneck from a catastrophic event or perhaps a disease that wiped out all but a few individuals.
No,it’s not. It’s evidence that populations are infinitely large, and so lineages coalesce eventually.
wd400,
The Eves that I imagine are H. sapiens. The common ancestor that you’re imagining is H. erectus . . . or earlier. That’s why I originally brought up chimpanzee mtDNA, which according to your conceptions are passed along through a common ancestor to humans.
The math simply demonstrates that a small sample size compared to a total population that’s large in comparison yields probability results that are asymptotic to an infinite population. Also, the math assumes perfect mixing without any isolated communities or density variations. Since you believe in Darwinism, I don’t need to remind you that isolation is a major factor in speciation. So, to discount a genetic bottleneck using this method robs you of speciation: you can either have an “infinite” population or you can have speciation, but not both.
But I’m willing to be convinced otherwise. Try the population experiment yourself using, let’s say 100 marbles of several colors. I’d be interested in your results.
-Q
The Eves that I imagine are H. sapiens. The common ancestor that you’re imagining is H. erectus . . . or earlier
Yes. So?
I really have no idea what you are talking about in the rest of this comment. I am not denying the existance of bottlnecks or genetic isolation. All I’m trying to say, and I don’t think it’s a hard point to grasp, is that your ‘eves’ themselves share a common ancestor from whom they must have inherited their mtDNA. Since ‘eve’ is the most recent common ancestor of human mtDNA that person would be today’s eve (even though she wasn’t eve at the time, and won’t be eve at some time in the future).
This would be true even if African European and Asian humans were different species or arose independantly.The onyl way around the inevitability of this would be multiple special creations.
wd400,
Me: The Eves that I imagine are H. sapiens. The common ancestor that you’re imagining is H. erectus . . . or earlier
You: Yes. So?
Me: Then, she wouldn’t be called a mitochondrial Eve, would she. Otherwise you could have a mitochondrial “Eve” for a planaria and a pussycat, which would be nothing more than the most recent common female ancestor.
Regarding the math, it’s really not that hard. Google it. Here’s a sample link:
http://emp.byui.edu/BrownD/Sta.....e_pops.htm
You might want to start with Part 2 of David Brown’s paper.
-Q
Mitochondrial eve is the most recent common ancestor of all humanity. There is no requirement she be the same (chrono-)species as modern human. Indeed, there are several genes seggregating in human populations that coalesce at a time prior to the human-chimp split.
If we want to recap this. The multiregionalists did not expect there to be multiple origins of humanity, even if they did such a scenario would not give rise to multiple eves, as, indeed mitochondrial lineages in any population will always be able to be traced back to a shared common ancestor. I don’t know why you are so invested in denieing these faces.
I know well enough about populations and samples. I don’t know why you think it is relevant. To use your hundred marble example: Start with a population of 100 labled individuals. Now, sample that population with replacement to simulate a new generation. Of course, some indiviuals will have more than one offspring and some will have none (their lineages die). Repeat this again and again and you’ll keep losing lineages until only one ‘ancestor’ is represnted in the population. That’s ‘eve’, and she emerged from a population that didn’t shrink at all.
It will take much longer for this process to happen in a lrage population (the expected time = 2N), but it can’t be avoided.
wd400:
Here are three separate comments made in three separate posts. I want to try and understand the implications of these comments below:
First:
Second:
Third:
It seems that population geneticists firmly believe that as time marches on, tests run to determine mt-Eve will uncover a different Eve.
Now, this must rest on the hypothesis that with time lineages simply ‘die out.’ I would think that the ‘idealized’ conditions of the model that is employed for RGD—viz, an ‘infinite number of alleles’ produced by each generation, out of which each ‘allele’ of the present generation is formed—adds to this likelihood.
But I see the net effect of this as rendering the entire project bankrupt of meaning. It’s as if you’re saying (actually you are saying this, though I scratch my head as to why—in the sense of it being a bankrupt notion) 100,000 years ago, if we could have done this test, we would have found a DIFFERENT mt-EVE; and, if we run this test 100,000 years from now, we’ll turn up another mt-EVE.
If you’re firmly convinced of that, then, as I say, this makes the whole technique devoid of content.
But it also makes things worse IMO. For example: what if a 100,000 years from now they determine that mt-EVE came out of Asia. Then what ever happened to the Out-of-Africa theory? Is it now untrue? This completely trivializes this theory.
And, as I try to remember back some 25 years or so, they were attempting to find out the various ‘sources’ of the human population; not necessarily ‘mt-EVE.’ IOW, they were testing individuals from various parts of the world knowing that the mitochondria are inherited along the maternal germ line, AND, if there had been multiple ‘origins’ of H.erectus, then this would mean they might find three completely different kinds of mt-DNA. When it turned out that all of the mt-DNA came from one single origin, Africa, they then began to speak of a mt-EVE. I don’t think the scientists were completely sure what they would find when they began the testing.
You mention that chimps have their own mt-DNA. Couldn’t there have been three different mt-EVEs for H. erectus (before they started testing; not afterwards)?
You said earlier that the RGD is used to determine ‘divergence times.’ Well, I guess it can do that. But, and this is you saying this, these ‘divergence’ times might almost be a constant over time—-which ends up telling us very little that we can put under the heading ‘certain.’
Apparently others agree with my assessment of mt-EVE.
Here’s this from Rick Groleau of PBS’s NOVAonline.
wd400,
Your first two sentences are self-contradictory. I don’t know how you would reconcile them. Also, I’m proposing that it makes sense in a Darwinist ideology for multiple emergences of H. Sapiens as well as aspects of multiregionalism.
I’m not invested in any of this—none of these speculations are facts (I assume you meant facts, not faces).
Take your 100 marbles and put them in an egg carton, dividing them into groups of zero to ten (or whatever fills a pocket in the tray). Now put the egg carton in your Prius, and drive over a bumpy road. The empty pockets are unfilled regions. Now do your sampling and replacement but do this pocket by pocket (along with adding some novelties without which Darwinism won’t work). You’ll find that the pockets protect genetic diversity.
-Q
PaV,
Right – so the fact mtEve lived in Africa is not a great big deal. The findings that multiregeionalism can’t really account for are (a) she lived very recently and (b) almost all the basal mitochondrial lineages are found in Africa. That’s exactly the patter OOA predicts (with non African populations mainly being a sub-sample of African genetic diversity + whatever mutations they added along the way). The population was very highly structured then the time to coalescence would be much greater, and there is no real way to explain the much greater diversity in Africa.
You mention that chimps have their own mt-DNA. Couldn’t there have been three different mt-EVEs for H. erectus (before they started testing; not afterwards)?
No. Or, there are distinct mitochondrial lineages in restricted to geographical regions (7 duaghters of eve and all that), they just aren’t Eves.
You said earlier that the RGD is used to determine ‘divergence times.’ Well, I guess it can do that. But, and this is you saying this, these ‘divergence’ times might almost be a constant over time—
Nope. Times to coalescence within one population would be constant abesent selection, fulcuting population size etc (that’s, after all, how we know there was no sever bottleneck…). But times to divergence are different because gene flow ceases and the lineages can no longer coalsece. If you use a single gene the estimaes of divergence times will be slighltly biased upwards since they will coalesce on some ‘eve-like’ individual who lived prior to the ceasatoin of geneflow, but modern methods account for this.
Querius,
Your first two sentences are self-contradictory. I don’t know how you would reconcile them
At this point I’m happy to mark that up as your failure rather mine. I don’t know why these facts are hard for you to reconcile.
Take your 100 marbles and put them in an egg carton, dividing them into groups of zero to ten (or whatever fills a pocket in the tray). Now put the egg carton in your Prius, and drive over a bumpy road. The empty pockets are unfilled regions. Now do your sampling and replacement but do this pocket by pocket (along with adding some novelties without which Darwinism won’t work). You’ll find that the pockets protect genetic diversity..
Structured populations lose genetic diversity, though they do make the time to coalescence in the ‘metapopulation’ longer, they don’t eliminate the absolutely inevetibaly phenomenom.
wd400,
Your statement number 1:
This statement seems to indicate that mitochondrial Eve is human, in other words H. sapiens.
Your statement number 2:
This statement indicates that mitochondrial “Eve” could be a different species (or chronopecies) entirely, which is NOT H. sapiens. But if the MCRA of ALL humans is a chimpanzee-like animal, you would be claiming that there is no common H. sapiens ancestor to all humans, which contradicts your first statement. The only way to make your second statement true is by parallel and convergent evolution—otherwise there WOULD be a human mitochondrial Eve.
You seem to be confusing the concepts of MCRA with mtDNA. They’re not the same thing.
Humbug. Especially for “infinite” populations. Go get 100 marbles of 3-4 different colors, an egg carton, and a Prius, and try it yourself!
Segregate the marbles according to color in the egg carton to represent isolated populations with a mutational difference as Darwinists claim happened for evolution to have occurred. Allow some scattering. Introduce a new colored marble occasionally but rarely to represent mutational novelties as is supposed to have happened according to Darwinists.
If you’re ambitious, write a simple app and show us. Have it count the number of generations. I think you’re in for a surprise. Remember, the more filled a pocket in the egg carton becomes, the more likely a marble will spill over into a neighboring pocket.
-Q
That you think this suggests you have a confused idea of either mitochondrial eve and population genetics or what a species is. I can’t tell which. (By the way, I should have said the most recent matrilineal common ancestor – the most recent common ancestor of humanity almost certinaly lived more recently than ‘eve’.)
Here’s Joe Pickrell making the same point about Y-chr adam (although, note, it seems even some population geneticists have made this mistake)
Which populations do know that are infinite?
I really have no desire to prove entry level pop gen.Population structure extends the time to coalescence, in the extreme case with no gene flow (i.e. speciation) the lineages will coalesce just prior to the cessation of gene flow, otherwise at some more recent time. Expanding populations are known to hold on to more diversity, and mutations allow us to relate lineages to each other,neither of these processes remove the inevetiability of the fact lineages coalesce eventually.
wd400:
But how, exactly, do you ‘prove’ “entry level population genetics”?
It’s all axiomatic. We’re using models, with idealized assumptions being made, and then refinements made to the idealized assumptions. You either have “confidence” in the models and their results, or you don’t.
As I pointed out earlier, the value of all of this becomes questionable. That you have to make a distinction between the “most recent matrilineal common ancestor” and the “most recent common ancestor of humanity” is an indication of the theory’s limited value.
See you tomorrow.
wd400,
Yes, matrilineal. And you haven’t answered my challenge of how our MRMCA could possibly not be Homo sapiens.
Statistically infinite populations were explained in the link that I provided:
http://emp.byui.edu/BrownD/Sta.....e_pops.htm
You should really try playing with the marbles. It will get you a feel for the dynamics. Besides direct observation should always trump theory. Right?
PaV,
Exactly!
-Q
And you haven’t answered my challenge of how our MRMCA could possibly not be Homo sapiens.
That’s because you simpyl assert that being the MRMCA of humanity means Eve is necesarily a modern human. There is absolutely no reason for that to be the case. Without seeing why you think this is the case it’s very hard to guess where your confusion arises from.
The statistical behaviour of samples from their large populations has almost nothing to do wit this question – as long as populations are actually finite then coalesnce will happen.
I have done the equivalent of your marble simulation many many times, as have thousands fo population geneticists. If you want to deny the findings of this field you will need to do better than though experiments about egg cartons and marbles.
Nice try, wd400, but I didn’t say modern human. I said Homo sapiens. There is an important difference!
The link that I provided indicated statistically infinite populations, and explained why. This is not my idea, and I object to the lack of factoring in genetically isolated groups, which I think is critically important.
And the “equivalent of your marble simulations” as you put it are not the same as Actually Performing One with actual marbles in an egg carton in your Prius! You seem to be reluctant to even try it. Don’t be a grouch, it will be fun! 😉
-Q
This is a waste of time.
Nice try, wd400, but I didn’t say modern human. I said Homo sapiens. There is an important difference!
What’s the imprtant difference? Why do yout thinkthe MRMCA of humans today had to H. sapiens?
The link that I provided indicated statistically infinite populations, and explained why. This is not my idea, and I object to the lack of factoring in genetically isolated groups, which I think is critically important.
The link doesn’t “indicate” “statistically infinite populations” in any relevant way – it’s about sample statistics and the fact you can sometimes safely assume the population from which a sample was drawn was is infinite when you do statistical tests. It doesn’t apply to this question at all, so far as I can tell.
I don’t ignore population strucutre, nothing about reduced gene flow prevents lineages form coalescening (thoug it slows that process). If populations are completely isolated then lineages will still coalesce at some time prior to the cessation of geneflow. Indeed if you treated humans and chimps as a single very structured population there would still be one “eve” for that combined population.
wd400 shot back:
Don’t worry, I read your post regardless. 😉
I’m astonished that you don’t know the difference between what we still recognize as Homo sapiens (in context, early modern humans) versus contemporary humans. Sorry, but you left out a word or two in your second sentence, so I don’t know what you’re trying to say.
The expressions that David Brown provided for a statistically infinite population does not recognize the effect of isolated populations—if you disagree, please point out the terms that do address them.
Nonsense. We don’t treat humans and chimps as a single structured population! Humans and chimps don’t and never have bred together. You should know this, so I can only conclude that you’ve decided to become disingenuous.
The marble experiment is a good place to help you understand the dynamics involved.
Goodbye.
I’m astonished that you don’t know the difference between what we still recognize as Homo sapiens (in context, early modern humans) versus contemporary humans. Sorry, but you left out a word or two in your second sentence, so I don’t know what you’re trying to say.
I know the difference, I even know the difference between modern humans and contempory humans if you want to play silly games. What I don’t know if why you claim the MRMCA of contempory humans has to be H. sapiens. Please explain that.
The expressions that David Brown provided for a statistically infinite population does not recognize the effect of isolated populations—if you disagree, please point out the terms that do address them.
The expressions aren’t about biological populations, so they have nothing to do with genetic isolation. What are you talking about?
Nonsense. We don’t treat humans and chimps as a single structured population! Humans and chimps don’t and never have bred together. You should know this, so I can only conclude that you’ve decided to become disingenuous.
I’m taking an extreme versoin of your position (that population structure can create multiple eves) and showing even then you claim doesn’t hold.
Now, please, in a simple sentence: why must the MRMCA of contempory humans be H. sapiens?