New research points to a 40 million-year-old split between the ancestors of humans and orangutans
| October 16, 2012 | Posted by vjtorley under Intelligent Design |
Human prehistory has descended into a state of chaos which can only be described as farcical. New research, summarized in an October 2012 review by Aylwyn Scally and Richard Durbin (“Revising the human mutation rate: implications for the understanding human evolution” in Nature Reviews Genetics 13:745-753, doi:10.1038/nrg3295) suggests that the molecular clock used to date events in hominid prehistory may run more slowly than previously thought, and at variable speeds, throwing the timetable of evolutionary events into confusion.
The new research has staggering implications for the date of the split between the lineage leading to orangutans in Asia and the line leading to humans, chimps and gorillas in Africa: it’s been revised from 13-14 million years ago to anywhere from 34 to 46 million years ago – an impossible result that has researchers scratching their heads.
A report by Ann Gibbons (“Turning back the clock: slowing the pace of prehistory.” Science 338:189-191) exposes the massive uncertainty than now reigns in the field of physical anthropology:
“The mutation rates are so up in air,” said paleogeneticist Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, in August, when his team published big margins of error — from 170,000 to 700,000 years ago — for the date when our ancestors split from Neandertals and their close cousins, the Denisovans. As a result, the timing of some events in human origins is now “very murky,” says paleoanthropologist Chris Stringer of the Natural History Museum in London. The ambiguity in the mutation rate affects a host of evolutionary and disease-related analyses, says paleoanthropologist John Hawks of the University of Wisconsin, Madison: “We can’t figure out how things happened if we don’t know when they happened.”
Before we go any further, let’s review the science underlying the molecular clock, which is used by paleoanthropologists to date events in our past. Matthew Cobb provides a handy summary in his post, Putting our DNA clock back, over at Why Evolution Is True:
The basic assumption behind the molecular clock is that mutations – changes in DNA – occur at a constant rate over time, and that the number of differences between two groups can therefore be turned into a figure based on the time since the two diverged. This phenomenon was first noticed in 1962 by Linus Pauling and Emile Zuckerkandl looking at differences in haemoglobin genes, then explicitly turned into a hypothesis the following year by Margoliash, before being fully developed in the 1970s by Allan Wilson. (It is in fact a bit more complicated, as the average generation time of a species has to be taken into account – the shorter the generation time, the higher the mutation rate.)
There are some important provisos to the clock – any stretch of DNA that is subject to selection, for example, is not going to be a very useful source of clock data, as genetic differences will tend to be removed by selection; many genes that are vital to organismal function are therefore highly conserved, showing few differences between groups. For this reason, scientists tend to use either ‘synonymous changes’ in DNA – these are ‘silent’ differences that do not cause any change in gene function (protein structure, gene regulation, or whatever) – or to use stretches of non-coding DNA, which appear to be not subject to natural selection and to evolve ‘neutrally’, just accumulating mutations with time.
As Ann Gibbons points out, the science behind molecular clock dating was relied on highly questionable assumptions, until very recently:
For the past 15 years, researchers have estimated the speed of the molecular clock by counting the mutational differences between humans and primates in matching segments of DNA, then using different species’ first appearances in the fossil record to estimate how long it took those mutations to accumulate. For example, the fossils of the oldest known orangutan ancestor are about 13 million years old, so DNA differences between humans and orangutans had about that long to accumulate. By doing similar calculations in many segments of DNA in various primates, researchers calculated an average rate of about one mutation per billion base pairs per year for humans and other apes…
But this method of calculating the mutation rate has drawbacks. For starters, it assumes that the fossil dates accurately record the first appearance of a species, but that can change with a new find. Second, there are no fossils of our closest living relatives: chimps and gorillas. Third, the method assumes that species split at the same time as their genes diverged, but in fact, genetic separation can be millions of years earlier than species divergence. Finally, the method assumes that mutation rates are similar across apes, although factors such as generation time—the average number of years between generations — affect the rate.
Now all that has changed:
With the recent advent of high-throughput sequencing methods, geneticists finally have been able to sequence enough whole genomes to calculate directly the number of mutations between trios of two parents and their child in large numbers of families. Eight studies in the past 3 years (and the 2003 study) have estimated a slower mutation rate, according to a review published online on 11 September in Nature Reviews Genetics by geneticists Aylwyn Scally and Richard Durbin of the Wellcome Trust Sanger Institute in Hinxton, U.K…
Remarkably, all the studies got about the same rate: 1.2 × 10^-8 mutations per generation at any given nucleotide site. That’s about 1 in 2.4 billion mutations per site per year (assuming an average generation time of 29 years) — and that’s less than half of the old, fossil-calibrated rate.
The new research has created an upheaval in the field of human evolution. The following table (adapted from Gibbons’ report) summarizes the old and the new molecular clock dates for some key events in human prehistory. As the reader can see, both the old and the new molecular clock are at odds with the fossil evidence on vital points.
Human-orangutan split
Fossil evidence
9 million–13 million years ago (Sivapithecus)
Old mutation rate
13 million–14 million years ago
New mutation rate
34 million–46 million years ago (Mismatch between fossils and molecular date)
Human-chimp split
Fossil evidence
4.1 million–7 million years ago (Sahelanthropus, Orrorin, Ardipithecus, and Australopithecus)
Old mutation rate
4 million–7 million years ago
New mutation rate
8 million–10 million years ago (Mismatch between fossils and molecular date)
Homo sapiens-Neandertal split
Fossil evidence
350,000–600,000 years ago (Homo heidelbergensis), 200,000 years ago (Neandertals)
Old mutation rate
250,000–350,000 years ago (Mismatch between fossils and molecular date)
New mutation rate
400,000–600,000 years ago
Out-of-Africa migration
Fossil evidence
125,000–80,000 years ago (archaic Homo sapiens)
Old mutation rate
Less than 70,000 years ago (Mismatch between fossils and molecular date)
New mutation rate
90,000–130,000 years ago
While the new molecular clock seems to give more accurate dates than the old clock for the more recent events in human prehistory, such as the split between Homo sapiens and Neandertal man and the migration of our ancestors out of Africa, it goes wildly astray for earlier events in our past. For instance, it places the human-orangutan split at 34-46 million years ago – which is a lot earlier than the date when apes diverged from monkeys, and about the same time as when Old World and New World monkeys diverged. Paleoanthropologists are not pleased. “A human-orangutan split at 40 million years is absolutely crazy,” says David Begun of the University of Toronto.
So how are scientists explaining the awkward dates implied by the new molecular clock? Scally and Durbin, in their report in Nature Reviews Genetics, suggest that the mutation rate was faster early on in primate evolution. Than, they say, it slowed in the African apes. After that, it may have slowed down even more in human evolution. Commenting on Scally and Durbin’s proposal, Harvard University population geneticist David Reich agrees that some slowdown did occur in the great apes. Nevertheless, in a supplement to a recent paper he and his research team published (Nature Genetics, 44, 1161-1165 (2012), doi:10.1038/ng.2398), he argues that the scenario proposed by Scally and Durbin is extremely unlikely:
However, this scenario also requires us to hypothesize a combination of unlikely events: (a) the slowdown would need to have been coincidental in both lineages to explain the observations, and (b) the slowdown would also have to have been extraordinarily dramatic: about 3-fold in both lineages in the period ancestral to human-chimpanzee divergence to produce as extreme an effect as is observed. (page 66) (Emphases mine – VJT.)
Reich himself believes that the new molecular clock methods aren’t picking up all the mutations, which is why he believes they’re getting an artificially slow mutation rate. Reich, Stefansson, graduate student James Sun of the Massachusetts Institute of Technology, and several other researchers have recently co-authored a study of their own (Nature Genetics, 44, 1161-1165 (2012), doi:10.1038/ng.2398) which used a different method, based on micro-satellite DNA, or small pieces of DNA which vary in the number of times they repeat, and which have a higher mutation rate than DNA nucleotides, making it easier to pick up all their new mutations. After converting the microsatellite mutation rates back to a base pair mutation rate, Reich and his team came up with a figure of 1 in 1.2 billion to 1 in 2.0 billion per year, compared with the figure of 1 in 2.4 billion mutations per site per year yielded by the new molecular clock studies. The rates proposed by Reich’s team would put the split between humans and chimpanzees at about 3.7 million to 6.6 million years ago, compared with a date of to 8 to 10 million years ago indicated by the new molecular clock. If Reich and his team are correct, the human-orangutan split would have occurred between 9.8 and 17.5 million years ago, or 2.65 times earlier than the human-chimp split. But Reich’s proposal faces problems of its own: it would imply that Sahelanthropus, and possibly also Orrorin and Ardipithecus, are not on the line leading to human beings, as anthropologists currently believe.
As Gibbons wryly observes in her article: “So no matter how researchers calculate the mutation rate directly, they can’t accommodate all the fossil dates.”
I was therefore puzzled when Matthew Cobb ended his post on the new molecular clock over at Why Evolution Is True, on an upbeat note:
A lot of unknowns remain – in particular the issue of estimating generation time in prehistoric populations, as well as the lack of population-level data for prehistoric groups (e.g. Neanderthals or Denisovans). But the increasing richness of molecular data are producing ever more refined estimates of our past. And that is the power of science – nothing is taken as fixed, knowledge changes and increases, in a uniquely progressive way, enabling us to revise and refine our understanding, and even to reject what we previously thought to be true. Indeed, there is grandeur in this view of life.
All I can say is: if this is what Cobb calls good news, what would he consider bad news? I’d invite him to consider again the four-fold uncertainty in the date of the split between Homo sapiens and Neandertal man: anywhere from 170,000 to 700,000 years ago. Or let him consider the near six-fold uncertainty in the date of the human-orangutan split: anywhere from 8 to 46 million years ago. Is this what Cobb calls progress?
And while I’m writing on the subject of orangutans, I’d also like to ask my readers to ponder the following question: why is it that humans share at least 28 unique physical characteristics with orangutans, but only two with chimps and seven with gorillas, despite the fact that we’re genetically closer to chimps and gorillas?
I’d like to close with a quote from Chesterton:
“Merely having an open mind is nothing. The object of opening the mind, as of opening the mouth, is to shut it again on something solid.” (Autobiography. Collected Works Vol. 16, p. 212)
52 Responses to New research points to a 40 million-year-old split between the ancestors of humans and orangutans
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29 years per generation? Is that a typo? Female chimps and orangutans can reproduce at 10. Perhaps earlier.
Why are they “(assuming an average generation time of 29 years)”? What am I missing?
Humans? 29 seems a tad long for humans too.
The point is if the generation time is halved that pulls the numbers either to a match or much closer.
VJT:
Because it ain’t necessarily about the genetics. It’s the way the genetics are used. Yeah baby, I’ze knowz my evolution.
Obvioulsy the orangutans’ environment/ fitness lanscape function thing, was such that it drove the formation of those characteristics, in a non-random feed-back hackey-sack, kind of way. And humans play hackey-sack, so there ya go.
“Human prehistory has descended into a state of chaos which can only be described as farcical.”
Not just humans. I read the other day that a number of studies on the genomes of falcons have shown that they’re apparently more closely related to warblers than they are to hawks.
Go figure.
Based on the evidence of the quoted paper:
1. Can you provide any evidence that contradicts common ancestry of the great ape lineage?
2. Do you propose, on the basis of the paper, an alternative phylogenetic structure (alternative to common ancestry) to explain the observed common embryological, developmental, fossil and genetic evidence shared by the ape clade?
4. Does the paper provide any evidence that humans do not fit inside the currently accepted phylogeny of the ape clade?
5. Do humans fit within any phylogenetic structure that you infer from the paper you quote?
timothya-
Is there are genetic evidence that says the physical transformations required (for humans to be descended from knucle-walkers/ quadrapeds) are even possible?
timothya,
etc.. etc.. etc..
timothya:
What would such evidence even look like?
Hi timothya,
Thank you for your post. I don’t contest the evidence for the common ancestry of humans and apes, or of apes in general. What I DO contest is the notion that neo-Darwinian evolution is adequate to explain the suite of changes in the human line, in the last few million years.
The current consensus as to precisely how and to what degree humans and great apes are related, is shown in the following diagram:
http://upload.wikimedia.org/wi.....inidae.PNG
There is however a minority view (championed by John Grehan and Jeffrey Schwartz) that orangutans are the closest relatives of human beings. See the following articles:
Evolution of the second orangutan: phylogeny and biogeography of hominid origins by John Grehan and Jeffrey Schwartz, Journal of Biogeography (2009) 36, 1823–1844.
Orangutans May Be Closest Human Relatives, Not Chimps . Commentary on Grehan and Schwartz’s paper.
Humans More Related To Orangutans Than Chimps, Study Suggests . Report on a 2009 study by Grehan and Schwartz.)
The ?rst humans, the second orangutan and the third chimpanzee . (Critical review of Grehan and Schwartz’s 2009 book.)
Hope that helps.
timothya,
I do contest the claim that humans and apes are related via common ancestry and say the evidence, the same evidence used for common ancestry, points to a common design.
However I do not categorically deny the possibility of human/ ape commn ancestry, it’s just that without first assuming it to be true, it is an untestable claim. But that may change someday and if I am alive when that happens, I will definitely listen.
Joe (8):
Common ancestry predicts that you will not find any Australopithicus, Ardipithecus, or Kenyanthropus fossils outside of Africa. We have not found any outside of Africa. If not proof is that not a strong argument for common ancestry?
And does that not make common descent falsifiable?
Here is how neo-Darwinian evolution avoids falsification from the fossil record;
“What Would Disprove Evolution?” – July 10, 2012
Excerpt: Fossils are found in the “wrong place” all the time (either too early, or too late). Paleontological theory, however, allows for such devices as “ghost lineages” to repair the damage; see ENV’s coverage here and here. (links on the site)
Again, discordance between molecular and anatomical phylogenies is commonplace in systematics; see here.(link on the site)
But we expect Coyne is able to handle these anomalies via his shock-absorbing adjective “complete,” which allows an indefinitely large range of possibilities, short of “complete” discordance (whatever that means).
http://www.evolutionnews.org/2.....61891.html
Seeing Ghosts in the Bushes (Part 2): How Is Common Descent Tested? – Paul Nelson – Feb. 2010
Excerpt: Fig. 6. Multiple possible ad hoc or auxiliary hypotheses are available to explain lack of congruence between the fossil record and cladistic predictions. These may be employed singly or in combination. Common descent (CD) is thus protected from observational challenge.
http://www.evolutionnews.org/2.....31061.html
The Fossil Record and Falsifiable Predictions For ID – Casey Luskin – Audio
http://intelligentdesign.podom.....6_42-07_00
You Won’t Believe How Evolutionists Say These Two Major Contradictions Cancel Each Other Out – March 2012
Excerpt: Evolutionists say without evolution nothing makes sense in biology, but it seems that with evolution nothing makes sense in biology.
http://darwins-god.blogspot.co.....s-say.html
Here is how evolutionists avoid falsification from the biogeographical data of finding numerous and highly similar species in widely separated locations:
More Biogeographical Conundrums for Neo-Darwinism – March 2010
http://www.evolutionnews.org/2.....32471.html
The Case of the Mysterious Hoatzin: Biogeography Fails Neo-Darwinism Again – Casey Luskin – November 5, 2011
Excerpt: If two similar species separated by thousands of kilometers across oceans cannot challenge common descent, what biogeographical data can? The way evolutionists treat it, there is virtually no biogeographical data that can challenge common descent even in principle. If that’s the case, then how can biogeography be said to support common descent in the first place?
http://www.evolutionnews.org/2.....52571.html
Here is another way neo-Darwinists avoid falsification from the evidence:
Convergence Convenience – October 8, 2012
Excerpt: Evolutionary theory has a classification scheme that cannot lose. Darwin’s original tree diagram described “divergent evolution,” a process beginning with speciation followed by the accumulation of variations that make the two branches more and more dissimilar over time. Animals with similar structures on the same branch are said to have “homologous” traits, because they derive from the same common ancestor. But the living world is filled with traits that resemble each other on different branches. What caused that? Ah, the evolutionist replies: those traits are due to “convergent evolution.” The similarities are “analogous” traits, because they do not derive from the same common ancestor. With this classification scheme, evolution explains everything: if similar animals are related, they evolved; if they are unrelated, they evolved. Is this a description of reality, or rather a convenient strategy for rendering evolution immune from falsification? Here are some recent examples of “convergent evolution” from the literature. (7 examples of ‘just so’ stories are cited),,,
,,,The Wikipedia entry on “Convergent Evolution” shows that the concept has undergone a bit of taxonomic diversification itself: there’s functional convergence, homoplasy, synapomorphy, parallel evolution, re-evolution and evolutionary relay. Convergence might be detected at the morphological level or at the molecular level. As for causes of convergent evolution, the article claims that animals with similar niches are likely to evolve similar equipment. And yet that can hardly be a “law of nature,” because many organisms occupy similar niches without “convergent” traits. Thus, they are divergent except when they are convergent – an explanation that explains opposite concepts. (and is thus impossible to falsify, i.e. heads I win, tails you lose!))
http://crev.info/2012/10/convergence-convenience/
related notes:
“these australopith specimens (Lucy) can be accommodated with the range of intraspecific variation of African apes”
Nature 443 (9/2006), p.296
“The australopithecines (Lucy) known over the last several decades from Olduvai and Sterkfontein, Kromdraai and Makapansgat, are now irrevocably removed from a place in a group any closer to humans than to African apes and certainly from any place in a direct human lineage.”
Charles Oxnard, former professor of anatomy at the University of Southern California Medical School, who subjected australopithecine fossils to extensive computer analysis; http://creationwiki.org/Australopithecines
Israeli Researchers: ‘Lucy’ is not direct ancestor of humans”; Apr 16, 2007
The Mandibular ramus morphology (lower jaw bone) on a recently discovered specimen of Australopithecus afarensis closely matches that of gorillas. This finding was unexpected given that chimpanzees are the closest living relatives of humans.,,,its absence in modern humans cast doubt on the role of Au. afarensis as a modern human ancestor.
http://www.arn.org/blogs/index.....cestral_li
“The australopithecine (Lucy) skull is in fact so overwhelmingly simian (ape-like) as opposed to human that the contrary proposition could be equated to an assertion that black is white.”
Lord Solly Zuckerman – Chief scientific advisor to British government and leading zoologist
Ardi: The Human Ancestor Who Wasn’t? – May 2010
Excerpt: “[White] showed no evidence that Ardi is on the human lineage,” Sarmiento says. “Those characters that he posited as relating exclusively to humans also exist in apes and ape fossils that we consider not to be in the human lineage.”
http://www.time.com/time/healt.....15,00.html
Later Hominins: The Australopithecine Gap – Casey Luskin – August 2012
Excerpt: Paleoanthropologist Leslie Aiello, who served as head of the anthropology department at University College London, states that when it comes to locomotion, “australopithecines are like apes, and the Homo group are like humans. Something major occurred when Homo evolved, and it wasn’t just in the brain.” The “something major” that occurred was the abrupt appearance of the human body plan — without direct evolutionary precursors in the fossil record.
http://www.evolutionnews.org/2.....62891.html
“Something extraordinary, if totally fortuitous, happened with the birth of our species….Homo sapiens is as distinctive an entity as exists on the face of the Earth, and should be dignified as such instead of being adulterated with every reasonably large-brained hominid fossil that happened to come along.”
Anthropologist Ian Tattersall
(curator at the American Museum of Natural History)
Here is how neo-Darwinian evolution avoids falsification from the fossil record;
“What Would Disprove Evolution?” – July 10, 2012
Excerpt: Fossils are found in the “wrong place” all the time (either too early, or too late). Paleontological theory, however, allows for such devices as “ghost lineages” to repair the damage; see ENV’s coverage here and here. (links on the site)
Again, discordance between molecular and anatomical phylogenies is commonplace in systematics; see here.(link on the site)
But we expect Coyne is able to handle these anomalies via his shock-absorbing adjective “complete,” which allows an indefinitely large range of possibilities, short of “complete” discordance (whatever that means).
http://www.evolutionnews.org/2.....61891.html
Seeing Ghosts in the Bushes (Part 2): How Is Common Descent Tested? – Paul Nelson – Feb. 2010
Excerpt: Fig. 6. Multiple possible ad hoc or auxiliary hypotheses are available to explain lack of congruence between the fossil record and cladistic predictions. These may be employed singly or in combination. Common descent (CD) is thus protected from observational challenge.
http://www.evolutionnews.org/2.....31061.html
The Fossil Record and Falsifiable Predictions For ID – Casey Luskin – Audio
http://intelligentdesign.podom.....6_42-07_00
You Won’t Believe How Evolutionists Say These Two Major Contradictions Cancel Each Other Out – March 2012
Excerpt: Evolutionists say without evolution nothing makes sense in biology, but it seems that with evolution nothing makes sense in biology.
http://darwins-god.blogspot.co.....s-say.html
Here is how evolutionists avoid falsification from the biogeographical data of finding numerous and highly similar species in widely separated locations:
More Biogeographical Conundrums for Neo-Darwinism – March 2010
http://www.evolutionnews.org/2.....32471.html
The Case of the Mysterious Hoatzin: Biogeography Fails Neo-Darwinism Again – Casey Luskin – November 5, 2011
Excerpt: If two similar species separated by thousands of kilometers across oceans cannot challenge common descent, what biogeographical data can? The way evolutionists treat it, there is virtually no biogeographical data that can challenge common descent even in principle. If that’s the case, then how can biogeography be said to support common descent in the first place?
http://www.evolutionnews.org/2.....52571.html
Here is another way neo-Darwinists avoid falsification from the evidence:
Convergence Convenience – October 8, 2012
Excerpt: Evolutionary theory has a classification scheme that cannot lose. Darwin’s original tree diagram described “divergent evolution,” a process beginning with speciation followed by the accumulation of variations that make the two branches more and more dissimilar over time. Animals with similar structures on the same branch are said to have “homologous” traits, because they derive from the same common ancestor. But the living world is filled with traits that resemble each other on different branches. What caused that? Ah, the evolutionist replies: those traits are due to “convergent evolution.” The similarities are “analogous” traits, because they do not derive from the same common ancestor. With this classification scheme, evolution explains everything: if similar animals are related, they evolved; if they are unrelated, they evolved. Is this a description of reality, or rather a convenient strategy for rendering evolution immune from falsification? Here are some recent examples of “convergent evolution” from the literature. (7 examples of ‘just so’ stories are cited),,,
,,,The Wikipedia entry on “Convergent Evolution” shows that the concept has undergone a bit of taxonomic diversification itself: there’s functional convergence, homoplasy, synapomorphy, parallel evolution, re-evolution and evolutionary relay. Convergence might be detected at the morphological level or at the molecular level. As for causes of convergent evolution, the article claims that animals with similar niches are likely to evolve similar equipment. And yet that can hardly be a “law of nature,” because many organisms occupy similar niches without “convergent” traits. Thus, they are divergent except when they are convergent – an explanation that explains opposite concepts. (and is thus impossible to falsify, i.e. heads I win, tails you lose!))
related notes:
“these australopith specimens (Lucy) can be accommodated with the range of intraspecific variation of African apes”
Nature 443 (9/2006), p.296
“The australopithecines (Lucy) known over the last several decades from Olduvai and Sterkfontein, Kromdraai and Makapansgat, are now irrevocably removed from a place in a group any closer to humans than to African apes and certainly from any place in a direct human lineage.”
Charles Oxnard, former professor of anatomy at the University of Southern California Medical School, who subjected australopithecine fossils to extensive computer analysis;
Israeli Researchers: ‘Lucy’ is not direct ancestor of humans”; Apr 16, 2007
The Mandibular ramus morphology (lower jaw bone) on a recently discovered specimen of Australopithecus afarensis closely matches that of gorillas. This finding was unexpected given that chimpanzees are the closest living relatives of humans.,,,its absence in modern humans cast doubt on the role of Au. afarensis as a modern human ancestor.
http://www.arn.org/blogs/index.....cestral_li
“The australopithecine (Lucy) skull is in fact so overwhelmingly simian (ape-like) as opposed to human that the contrary proposition could be equated to an assertion that black is white.”
Lord Solly Zuckerman – Chief scientific advisor to British government and leading zoologist
Ardi: The Human Ancestor Who Wasn’t? – May 2010
Excerpt: “[White] showed no evidence that Ardi is on the human lineage,” Sarmiento says. “Those characters that he posited as relating exclusively to humans also exist in apes and ape fossils that we consider not to be in the human lineage.”
http://www.time.com/time/healt.....15,00.html
Later Hominins: The Australopithecine Gap – Casey Luskin – August 2012
Excerpt: Paleoanthropologist Leslie Aiello, who served as head of the anthropology department at University College London, states that when it comes to locomotion, “australopithecines are like apes, and the Homo group are like humans. Something major occurred when Homo evolved, and it wasn’t just in the brain.” The “something major” that occurred was the abrupt appearance of the human body plan — without direct evolutionary precursors in the fossil record.
http://www.evolutionnews.org/2.....62891.html
“Something extraordinary, if totally fortuitous, happened with the birth of our species….Homo sapiens is as distinctive an entity as exists on the face of the Earth, and should be dignified as such instead of being adulterated with every reasonably large-brained hominid fossil that happened to come along.”
Anthropologist Ian Tattersall
(curator at the American Museum of Natural History)
Jerad:
Why? In what way is that a “prediction” of common ancestry?
Also I was at the Smithsonian in Washington DC and I am sure they had such fossils there. Last I checked DC was outside of Africa. 🙂 (sorry I couldn’t resist)
Joe (11):
Since the common ancestor and the early parts of the descent lines are found in the same area of the same continent as you would expect if they were related. If apes and humans did not share a common ancestry then the early forms of each could be found far removed from each other.
🙂 Some of what you saw might have been copies actually. Apparently lots of what’s on display are not originals. Kind of disappointing but I guess they can’t lets us rabble get close to the real stuff.
Jerad:
So they couldn’t move? No geological isolation, which occurs when they move? What drove the speciation events if they were all subject to the same fitness landscape function algorithm?
Or perhaps you want to rethink that…
Joe (13):
And they did move later. Orangutangs, which split off from the common line earlier moved. And the later hominids emigrated out of Africa. What drove the speciation? No way to know for sure without having been there. I live in England and until the last century many people never moved more than a few miles from the place they were born. The point being that geographic isolation can be quite short distances especially for less intelligent creatures. Not birds so much though. Some anthropologists hypothesise that humans evolved from the ‘tribes’ that spent more time on the plains than in the trees. Perhaps it was the uprights vs the ‘knuckle draggers’ as you put it. No way to know for sure. But, pretty clearly, both lines came from the same general area and developed in close proximity until some early humans found greener pastures. Some humans stayed. The apes got stuck and are now endangered partially ’cause they’re ‘trapped’ in their environmental niches. Too bad they can’t evolve on command eh? Within our lifetime some apes may not exist in the wild anymore. Makes me wish there was a designer who could intervene.
Nah, I’m good.
From the OP:
So how are scientists explaining the awkward dates implied by the new molecular clock? Scally and Durbin, in their report in Nature Reviews Genetics, suggest that the mutation rate was faster early on in primate evolution. Than, they say, it slowed in the African apes. After that, it may have slowed down even more in human evolution. Commenting on Scally and Durbin’s proposal, Harvard University population geneticist David Reich agrees that some slowdown did occur in the great apes. /i>
Let me translate this for you: they don’t have a clue as to what actually happened.
Nor, likely, will they ever. Why? Because they’re wedded to neo-Darwinism, which can’t explain any of this (as vjtorley notes), and so they must twist facts and data until it has some chance (in their minds) of making sense.
So they couldn’t move? No geological isolation, which occurs when they move? What drove the speciation events if they were all subject to the same fitness landscape function algorithm?
Why not sooner? Your story tells me that this isn’t any prediction of common ancestry. As you said orangutans moved and they are tree dwellers and perhaps good swimmers at one time. 🙄
I wonder if there is a likely upper limit and likely lower limit at which they would consider such mutation rates might occur? I think we should be told.
Joe (16):
I don’t know why they didn’t move earlier. No one does. It is consistent with common descent, i.e. genetic lines that have a common root will coexist geographically for some time. Look at your own family history. It’s not hard.
Who can say? We weren’t there. If I asked you how and when your great-great-grandparents conceived your ancestor you’d have to make educated guesses. What else can you do? Look for evidence, clearly. Make intelligent guesses, of course. Know for sure .. . . uh huh. Keep dreaming.
From a February article in Evolution News, today:
http://www.evolutionnews.org/2.....56771.html
Plus ca change…
Mutation rates have been shown to increase plenty of times. In Dr. Lenski’s e coli experiment, 4 of the 12 strains had mutations that broke their DNA repair mechanisms which caused them to mutate faster.
But have we ever observed a mutation that improved DNA repair?
This is a really interesting study! In the 1980s, I remember it was a major coup for genetic-based phylogenies when fossil evidence discounted Ramapithecus from being a hominid ancestor. (The problem, remember, was that Ramapithecus was about 10 million years old, and the genetic data indicated that hominids split off from other apes around 5 million years ago.) So when Ramapithecus was folded into Sivapithecus, the genetic phylogenies were seemingly vindicated. But it rests on this assumption that we’ve got a stable “molecular clock,” ticking away at a steady and easily-calculable rate, and I’ve worried about that assumption for a while. And unfortunately we can’t sample DNA from extinct species.
My own family history- My mother’s parents came over from Italy. My dad’s, dad’s family came over from France via Canada- well I have a great, great, great grandmother who was a Micmac with roots in New Brunswick, CA. I don’t know much of anything about my dad’s mother- she died in the 1920s and he never talked about her, not to me anyway.
My daughter has roots and relatives in Argentina and more relatives in Australia.
Yeah, we’re pretty local…
OT:
Those ancient jawed fish had a mouthful of teeth, too – 10/17/2012
Excerpt: “It has long been thought that the first jawed vertebrates were gummy — (they had) jaws without teeth, capturing prey by suction-feeding,” ,,,
Donoghue and his colleagues analyzed 370-million-year-old fossils of a diverse and extinct group of armored fish known as placoderms, the first-known jawed vertebrates.,,,
The placoderm teeth had components seen in modern teeth, such as dentin, the hard, dense bony tissue forming the bulk of the tooth beneath the enamel, and a pulp cavity, which creates dentin. “We show that the juveniles had teeth for processing and capturing prey before they were worn away in the adults,” Donoghue said.
This discovery that the earliest jawed vertebrates were toothy suggests teeth evolved (were designed) along with or soon after jaws did.
http://www.msnbc.msn.com/id/49.....H9kUoYsE30
Joe posted this:
Do you have any examples of common design from the assemblage of extant species (I mean examples that show that a “design intervention” actually occurred to cause the resultant phenotypes?
Who, when, where, how and for what purpose would help me to understand your thinking.
vjtorley posted this:
I’m sorry, but on my reading, your post means that you do contest the common ancestry of the ape clade (including humans). If natural processes (according to you) are incapable of generating the observed variety of current ape types, then something other than common ancestry must have been involved.
You can’t have it both ways.
What was this something? When did it happen? In what way did it happen? Where can we find evidence of these non-common-ancestry events? By what agency? I will leave aside the question of the agency’s putative purpose, since that would be tendentious.
timothya-
Linnean taxonomy was based on the premise of a common design. Evos stole his idea and are now using it to support their “theory”.
Do YOU have any examples of random mutations accumulating in such a way as to give rise to the changes required? No, you have nothing.
When diod thos mutations occur? How many were required? You have NOTHING.
Deal with it
Joe posted this:
Human chromosome 2.
Explain it with design causes.
timothya-
What changes did HC2 bring about? Please be specific as to why natural selection favored that fusion.
Also you did know that the fusion occurred in the human lineage and as such has NOTHING to do with common ancestry with chimps.
HC@ from a design perspective:
Even before the release of “Science and Human Origins” there has been an uproar over human chromosome 2, the alleged fusion of two other chromosomes (still found in other primates) and sharing a common ancestor with chimps. According to evos this was supposed to be a chromosomal fusion that occurred in some gamete and then got passed along- a random event.
However if we look at it from a design perspective the randomness disappears. Why? Chromosome/ DNA packaging and chromosome territories.
Ya see gene expression and regulation depend on both the packaging and the location of the chromosomes within the nucleus, ie chromosome territories. And if you have two different/ separate chromosomes then they can be packaged differently and ferried around separately also, meaning they can be separated and placed in different territories.
So perhaps with humans it is required that the information never be separated. And the easiest way to accomplish that was by splicing the two together. Snip off the excess and splice.*
The research would be to determine where HC2 resides in certain tissues and cells and during development and then compare with the two primate chromosomes for the same tissues/ cells and stages of development.
So HC2 is explained as a design feature, for humans. It not only helps with reproductive isolation but it also allows for a different gene expression and regulation pattern necessary for the different requirements of humans.
* it could also be that the two chimp chromosomes were the result of splitting HC2 into two separate chromosomes
timothya you claim that if common ancestry were true (which I personally don’t find common ancestry to be true) that this supposed evidence for common ancestry would automatically imply that atheistic naturalism was true. Yet this is simply not the case. Common ancestry, even if true, could very well be driven by intelligence instead of by atheistic naturalism. Dr. Dembski makes this very point in his Conservation of Information paper:
In fact Dr. Plantinga has pointed out that common ancestry (evolution) and naturalism don’t go well together at all and has used common ancestry to argue against the truthfulness of naturalism:
footnote:
When a atheist claims something occurred ‘naturally’, to him this ‘naturally’ means that God was not involved in the ‘natural’ event in any way, shape, or form. But underlying this ‘naturalistic’ presupposition of the atheist is the belief that material particles of the universe are self-sustaining. Yet advances in quantum mechanics have undermined this ‘naturalistic’ belief and shown that the material particles of the universe are dependent on a transcendent, non-local, cause that is not limited by time or space. Theists have always held that God sustains reality in its existence:
Quantum Mechanics has now been extended by Anton Zeilinger, and team, to falsify local realism (reductive materialism) without even using quantum entanglement to do it:
i.e. a transcendent, ‘non-local’, cause must now be supplied to explain exactly why material particles (photons in this instance) continue to exist in this universe
verses and music:
supplemental notes:
Joe posted this:
Can I get this right? You are arguing that the “splicing event” was required in order to lead to the human lineage?
timothya-
What changes did HC2 bring about? Please be specific as to why natural selection favored that fusion.
That is a possibility. Now answer my question or admit that you are a coward.
Joe posted this:
Do you want to know where the biochemeical functions from the two unfused ancestral chromosomes ended up? Can’t help you unless you list what the functions actually were.
Specifically, natural selection does not favour any particular future outcome (hint: NS is not teleological). NS simply filters out phenotypes that are less successful in the current environment.
Once you understand this idea, we can move on to discussing actual science instead of your fantasy version.
Ummm I have to back up a bit . . .
Joe posted this:
Now there is your problem. Has it occurred to you that the fusion event might be one of the things that caused the divergence between the chimp and human lineages?
There is all that supporting evidence about the contents of of the human chromosome 2 that map onto the unfused chromosomes in the chimp lineage. But that isn’t really evidence, is it?
Hope that answers your question.
timothya:
Nope. I want to know what the fusion did and why it was favored enough to become fixed.
Umm the fusion happened so natural selection is relevant. There wasn’t any future outcome as the event occurred. Then somehow the fusion became fixed. why?
Actually NS is supposed to be a designer mimic, but yes it is really only a result and whatever is good enough gets through the filter.
And about science, you don’t seem to understand what science is.
timothya:
Yes, but that is NOT what is being said. I am just going by what evolutuionary biologists have said. Perhaps you should read up and stay current.
The current evolutionary thinking is that the split occurred and THEN came the fusion.
timothya:
Evidence for a common design.
What you don’t know is how many mutations were required for the transformation, when those mutations occurred nor what effect they had. And on top of that you don’t know if any amount of mutational accumulation can get teh job done.
Joe posted this:
In principle this sequence of events is possible, but what cites support your contention?
The fusion is only in humans- perhaps you should just read the literature. It’s all in there.
timothya:
NS is not teleological.
NS is teleological.
Just brilliant.
Hi timothya,
Thank you for your post. I appreciate meaty questions, and I’m glad you asked me some.
First, I’d like to clear up the issue of common ancestry. You wrote:
Of course, I believe that “something other than common ancestry must have been involved.” I’ll explain why below. When I say I believe in common ancestry, I simply mean that I believe there was a creature (possibly Proconsul) who was ancestral to all living apes and humans. However, I believe that God engineered key steps in the evolution of the human lineage.
You ask:
The “something” that took place was the intelligent engineering of the human genome, and it seems to have happened in four phases: 3.5 million years ago, 1.8 million years ago, 700,000 years ago and 200,000 years ago. The articles I’m relying on for my information are the following:
Evolution of the Brain in Humans – Paleoneurology by Ralph Holloway et al., The New Encyclopedia of Neuroscience, Springer, 2009, pp. 1326-1334.
Neural correlates of Early Stone Age toolmaking: technology, language and cognition in human evolution by Dietrich Stout et al., Philosophical Transactions of the Royal Society of London B, Biological Sciences, 2008 June 12; 363(1499): 1939–1949.
The First Appearance of Symmetry in the Human Lineage: where Perception meets Art (careful: large file!) by Dr. Derek Hodgson. In Symmetry, 2011, 3, 37-53; doi:10.3390/3010037
Paleolithic public goods games: why human culture and cooperation did not evolve in one step (abstract only available online), by Benoit Dubreuil, in Biology and Philosophy (2010) 25:53–73, DOI 10.1007/s10539-009-9177-7.
Holloway et al. write:
Despite the lip-service given to the neo-Darwinian theory of evolution in the article, I’m inclined to think that the two changes described by Holloway et al. were the product of engineering. The explanations proposed by Holloway et al. are “teleological” (the changes occurred in response to ecological changes, or to selection pressure favoring the evolution of language). Explanations like these tell us “why” but not “how.”
We also forget that the human brain is the most complex machine known in the universe. We know that random changes plus non-random “selection” are not enough by themselves to create a pattern or a function. As Professor William Dembski puts it in Conservation of Information Made Simple:
If someone wants to argue that random copying errors plus non-random death are sufficient to make a brain with new cognitive abilities, I shall demand evidence before I believe such a claim.
The best “evidence” I’ve seen to date is this paper:
Moving primate genomics beyond the chimpanzee genome by Morris Goodman et al., in TRENDS in Genetics, Vol.21 No.9, September 2005. The essay disappointed me with its vagueness. A quote:
The authors didn’t probe deeply enough. How many protein components are involved in energy production? Would the changes need to have occurred in a particular sequence, or would they have been beneficial independent of the sequence in which they originated? What about the nine cytochrome c oxidase subunits which showed bursts of change? Did these changes occur independently of one another, or did they need to be choreographed? We don’t know. “Darwinian evolution must have done it” is the authors’ mantra.
Next, I’d like to look at tools. Stout et al. (2008) discuss the cognitive requirements that went into making Oldowan tools (which first appeared 2.6 million years ago) and Acheulean tools (which appeared shortly after the emergence of Homo ergaster/erectus, about 1.7 million years ago). The cognitive demands involved in making Oldowan tools don’t seem terribly rigorous. Acheulean tools demand a lot more careful co-ordination and sequencing, but can still be made without the need to mentally rehearse what you’re going to do. In other words, they don’t require truly human mental capacities.
So with Homo ergaster/erectus, it seems we are on the threshold of humanity, but not quite there yet.
Hodgson (2011) argues that later Acheulean handaxes have distinctively aesthetic features – in particular, a concern for symmetry. See especially the handaxes in Figure 1 on page 40, which dates back to 750,000 years ago – either at or just before the time when Heidelberg man emerged. Here’s a relevant quote:
Finally, I’d like to focus on changes in the prefrontal cortex that took place about 700,000 years ago, with the emergence of Homo heidelbergensis (Heidelberg man), and in the temporoparietal cortex, with the emergence of modern Homo sapiens, about 200,000 years ago. The authors argue that Heidelberg man, because of his enlarged prefrontal cortex, was capable of delayed gratification and of putting himself in danger for the sake of realizing group goals (e.g. hunting a mammoth with wooden spears, which would have been a very risky enterprise) as well as long-term goals (e.g. raising a family). After Heidelberg man, no further enlargement of the prefrontal cortex took place. Humans were fully capable of long-term planning even 700,000 years ago. Instead, the braincase became more rounded, and finally, around 200,000 years ago (give or take 100,000 years), the capacity for symbolic art emerged. Here’s the abstract of Dubreuil’s article:
Here’s a quote from Dubreuil’s paper:
The big question is: was the emergence of symbolic consciousness 200,000 years ago merely icing on the cake, or was it the final change that made us fully human? I incline towards the former view. If you look at the handaxes people were making 750,000 years ago, you can already see aesthetic traits. Moreover, Dubreuil believes that Heidelberg man must have already had a capacity for language, and he certainly had a fully human capacity for long-term planning, long-term commitment (rearing a family), delayed gratification and self-sacrifice. Self-sacrifice for the sake of group goods would also require some sort of theory of mind, so it must have been present in Heidelberg man. Thus I would be inclined to see the changes that took place 200,000 years ago as a refinement rather than a fundamental change. I’d guess that for the first time, humans became able to personify objects, and endow the forces of Nature with a mind (animism). That’s very useful for artistic creativity, but I wouldn’t view a being lacking such an ability but possessing a capacity for long-term planning as sub-human.
Nevertheless, I’m also inclined to think that these most recent changes, which occurred 200,000 years ago, were also the product of design.
Well, I hope that answers your questions, timothya. That’s about as far as I’ve gotten, to date.
timothya:
What would such evidence even look like?
Mung:
Teleology in biology is your gig, not mine.
If you imagine teleology is involved in natural selection, then which is the intentional agent – the environment doing the selecting, or the organism whose variation is being selected?
Mung also posted this:
Evidence supporting a supernatural intervention, would be good for a start.
timothya:
No, it doesn’t. NS is not some filter letting some things pass out of the container while keeping some other things inside the container.
Organisms in a population which leave on average fewer offspring than some other organisms filter themselves out.
Organisms which leave more offspring will be represented in greater numbers in future generations. That’s all there is to ‘natural selection.’
And if NS is a filter, then it is teleological, since filters are teleological. All I’m pointing out is that you need to make up your mind about which version of NS you’re going to appeal to.
Rather than think of “natural selection” as some thing does the filtering, it’s better to think of natural selection as a name for the process whereby maladaptive traits tend to be less prevalent across a population. (Sometimes those traits are eliminated entirely, but often they aren’t.)
Importantly, that’s consistent with the thought that organisms themselves are teleological, in a certain way. For what it’s worth, I highly recommend “Life After Kant: Natural purposes and the autopoietic foundations of biological individuality” by Andreas Weber and Francisco Varela, for those of you interested in teleology and biology.
If teleology is involved then it ain’t natural selection. That is because NS is supposed to be a designer mimic, not a design mechanism.
NS is nothing more than differential reproduction due to heritable random, as in chance events per Mayr in “What Evolution Is”, variation(s).
However there can be differential reproduction without the “heritable random variation”. But only the first scenario is natural selection. Differential reproduction due to anything else is just the luck of the draw.
Personally I think natural selection is teleological.
http://philpapers.org/rec/WEBLAK
Mung posted this:
It is difficult to see how a sentient entity can think in any other way than personally.
But if someone is able to convince themselves that inanimate processes have intentions, I can only suppose that he or she can anthropomorphise any number of unlikely things.
Hence the notion of fiction.
timothya:
hypocrite
process:
1. a systematic series of actions directed to some end
teleological
Mung.
Do you use the term “directed” to mean “directed by an intelligence”?
timothya is bummed because natural selection doesn’t do anything…
vjtorley posted this:
Fair enough, your religious beliefs are clear.
You can subsume intelligent design into the concept of common ancestry if you wish. For me, it makes a nonsense of the idea. I would use the term “common ancestry” to include no more than the ordinary, observable processes of biological inheritance, reproduction and development. It is a stretch to include supernatural events, but it is your blog, after all.
In any case, if we accept the notion that your God intervened in the course of human ancestry, how are we to tell when and where it happened? Is it only in the critical turning points? Or did God fiddle with all those parts of the human genome that have “function”, but aren’t conserved through inheritance?
(By the way, you might consider whether the claim that “biochemical function” is ubiquitous in the human genome undermines the ID “needle in the haystack” argument).
And this:
[For the benefit of readers, the “something” reference applies to a previous post of mine upthread]
None of quotes from the papers that you provide claim that the ancestral human brain was intelligently engineered – that is an overlay based on your inclination in the direction of anthropomorphising natural processes.
And this:
I acknowledge your inclination, I reject your version of events and substitute reality.
1. Your use of “or” is misleading to the reader. Ecological changes (by definition) are changes to the environment in which the target species lived – that is, they represent the selective pressure that leads to evolutionary change. Whether the specific environmental changes led to the development of language as a consequence of genetic change in the ancestral species is unclear. Thus far we can go at present, but no farther.
2. Your version of “teleological” when applied to biological processes is peculiar to this blog. It isn’t shared by any biologist whose material I have read, though I am prepared to stand corrected. If I understand you, “teleology” does not necessarily carry the connotation of “intention”. Correct me if I misunderstand your use of the term.
And this:
Cut the researchers some slack – they didn’t set out to answer the question you pose.
But anyway, do we have any clues to whether “we don’t know” whether natural, undirected processes can generate novel protein synthesis pathways? By golly, we do know! . . . Lenski’s experiment demonstrates an example . . . and not only that, the mutational and selectional pathways involved have been specified, just in case we missed the improbabilities involved.
In passing, Ann Gauger reportedly made a similar claim concerning her own research at a conference organised by the Discovery Institute.
And this:
I can already see aesthetic traits, can I? You don’t need me to point out the notorious difficulty in deciding questions of aesthetic content. Your aesthetic inclination might be my functional necessitarianism. But your inclination is again noted.
And this:
Are inclinations additive or multiplicative? Having reviewed standard scientific publications (none of which identify any intelligent design interventions in the history of human evolution), you remain canted in the direction of the design assertion. I remain unenlightened about method, mechanism, evidence or, most importantly, purpose.
And finally this:
No, you haven’t. But thanks for the reading.