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Common ancestry from what, exactly?

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The first of some responses to persons who have kindly wrote in to “Some thoughts on common ancestry”:

Mark Frank writes

Whatever problems there may be in explaining the OOL they have no relevance to common ancestry. However it happened, life did begin (unless you are determined to discard cosmology as well as biology).

The relevance to common ancestry is: Common ancestry from what, exactly?

If we don’t know what, how do we know that?

It sounds appealing. Is it true?

Note: See the Science Fictions series at your fingertips (origin of life) for why origin of life is such a sinkhole in science today.

Next: Why, exactly, should we believe that humans are descended from simpler forms of life?

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19 Replies to “Common ancestry from what, exactly?

  1. 1
    Sirius says:

    Testing, test test.

    Sirius

  2. 2
    wd400 says:

    Big bang from what, exactly?

    We can trace lineages back and note they coalesce with having to know precisely what to call that coalescence.

  3. 3
    Mark Frank says:

    I am going to expand on this a bit:
    From previous OP:

    The relevance to common ancestry is: Common ancestry from what, exactly?
    If we don’t know what, how do we know that?

    By considering the alternatives.  To claim that we are not descended from a simpler life form at all is to claim we sprang into existence fully formed.

    But I also clearly see that current explanations of the human mind, vs. the chimpanzee mind, absolutely do not make sense. And that’s the money shot.

    It is absolutely  not the money shot. Biologists are not proposing that people are descended from chimpanzees!  They are only proposing we have a fairly recent common ancestor. The only implication is that we have changed a lot since then.

    But no one has a reasonable explanation of human consciousness. And great physicists warn that it is immaterial.

    Whether it be material or not, there is no reason to suppose that many other life forms are not also conscious. Any dog owner can tell you that. Clearly human consciousness is a big step up from other animals. So that step up happened at some stage in the recent past. This is perfectly compatible with being descended from simpler life forms.
    In general however unique you believe we are – the jump from a simpler (but nevertheless complicated) life form to us is shorter than the jump from no life form to us.  Even if you believe we are the result of divine intervention it is going to be a lot easier for God to make a major upgrade to some ape like creature than create enough people to make a viable community in a flash of lightening and a whirl of dust.

    With nothing compelling us to make a decision, we can just safely doubt current, insufficiently justified claims

    You may doubt specific claims about descent. But if you doubt descent at all then you need an alternative more plausible hypothesis. Let’s hear it.

  4. 4
    johnspenn says:

    MF said “Even if you believe we are the result of divine intervention it is going to be a lot easier for God to make a major upgrade to some ape like creature than create enough people to make a viable community in a flash of lightening and a whirl of dust.”

    Not true, my friend. If God did indeed create the entire universe and everything in it, then creating a human being “in a flash of lightening and a whirl of dust” would be a piece of cake.

    PS He didn’t need the lightening, but He may have used it for dramatic effect.

  5. 5
    drc466 says:

    We can trace lineages back…

    This is why it is hard to argue with evolutionists. They honestly believe this to be true. wd is not lying, whether correct or not.
    Link: These Tiny Rock Hyrax Babies the Closest Living Relative to the Elephant

    Small and stocky and resembling miniature adults almost immediately, Rock Hyrax babies weigh just a few ounces! But despite their Guinea pig-like appearance, the species is in fact the closest living relative of the elephant

    Really? Can they interbreed? Do you have a fossil candidate for a common ancestor? How “close” a relative is it? Is that a genetic assessment, or a morphological one? If genetic, what % of DNA is common? If morphological, based on what characteristics? How do you know those are the right characteristics? If they look like Guinea pigs, why not choose those characteristics (fur, legs, noses, ears) instead of the elephantine ones (hooves, hearing, gestation)? Do evolutionist pick the same morphological characteristics for the entire “tree of life” (hint: no)? How do they handle major changes in form (e.g. sexual, vertebrate, flight, etc.)?
    Quick: name one piece of raw scientific evidence that unequivocally excludes any theory of origin of life in favor of common ancestry. You can’t. In some cases common ancestry appears more parsimonious – but in others it just appears ridiculous (e.g. “convergent evolution” or “homoplasy”).

    @Mark: The fossil record indicates that, however life appears, it appears fully formed and complex. It is what it was, with allowances for variation built-in (e.g. dog types). As a YEC, special creation qualifies to me as a “more plausible” theory than common descent. I’ll let non-YEC ID answer for themselves.

  6. 6
    Joe says:

    Mark Frank:

    To claim that we are not descended from a simpler life form at all is to claim we sprang into existence fully formed.

    Or we can claim that we just don’t know. And coming from a simpler life form still needs a mechanism-> hint: natural selection isn’t up to the task.

    They are only proposing we have a fairly recent common ancestor.

    They still need a way to test that proposition. How many mutations did it take? What genetic changes were involved? However no one even knows what makes a chimp a chimp nor a human a human.

    But if you doubt descent at all then you need an alternative more plausible hypothesis.

    But descent isn’t even a plausible hypothesis- heck you can’t even get beyond prokaryotes without magic.

    The design hypothesis is as follows- Darwinism, Design and Public Education page 92:

    1. High information content (or specified complexity) and
    irreducible complexity constitute strong indicators or hallmarks of (past) intelligent design.

    2. Biological systems have a high information content (or specified complexity) and utilize subsystems that manifest irreducible complexity.

    3. Naturalistic mechanisms or undirected causes do not suffice to explain the origin of information (specified complexity) or irreducible complexity.

    4. Therefore, intelligent design constitutes the best explanations for the origin of information and irreducible complexity in biological systems.

  7. 7
    Mapou says:

    Mark Frank:

    By considering the alternatives. To claim that we are not descended from a simpler life form at all is to claim we sprang into existence fully formed.

    There is no question that there is a hierarchy of genetic design: complex things are made of simpler things. In fact, intelligent design over time always leads to a hierarchy. But it does not have to be common ancestry in the Darwinian sense. An evolution of design is all it was.

    Having said that, if given a choice between an all-powerful, all-knowing God and Darwinian evolution, I would choose the the latter because the former is illogical, IMO.

  8. 8
    wd400 says:

    So, here’s a question for drc446 or anyone else.

    When does molecular phylogeny stop working? I don’t think anyone objects to the finding the humanity originated in Africa, which is based on molecular phylogeny and population genetics. Same goes for our relationship to Neanderthals (and neanderthal introgression). The step from these findings to the((Human,Chimp)Gorilla) relationship is no great (indeed — there are some genes for which you have a copy more closely related to a chimp’s copy than to some humans).

    So when to does phylogeny stop working, and how to we know?

  9. 9
    DavidD says:

    Silicone Spray on Steroids “I don’t think anyone objects to the finding the humanity originated in Africa, which is based on molecular phylogeny and population genetics.”

    I object and so do most of my friends from Africa who are sick of being compared to looking like Apes and Monkeys. Of course a documentary was made about this Scientific Racism

    https://www.youtube.com/watch?v=3FmEjDaWqA4

  10. 10
    Joe says:

    wd400- Molecular phylogeny works fine to root out a common design.

  11. 11
    wd400 says:

    DavidD,

    Noting that humanity arose in Africa does not imply that modern Africans are any more or less related to other apes than the rest of humanity.

    Joe,

    I don’t see how, but lets move on. Were the various human populations around the world separately designed? How about neanderthals and modern humans? How would you tell the difference?

  12. 12
    drc466 says:

    @wd400,

    First, let me point out that a) molecular phylogenies are relatively new, b) molecular phylogenies can only compare modern species’ genetic code. So we can’t do a “molecular phylogeny” on australopithecus, because we lack their DNA (probably – evolutionary ideology puts blinders on scientists who might otherwise look for australopithecus DNA in fossils). So, one answer to your question is molecular phylogenies fail when you try to tie to any non-modern species. It can find similarities between ape/human dna, but it can’t prove common ancestry because you don’t have molecules from a common ancestor.

    Second, molecular phylogenies suffer from the same weaknesses as morphological – the answer you get depends on what you compare. If you compare hemoglobin, for example, crocodiles are closer to chickens than vipers.

    Mostly, though, from a YEC-perspective, molecular phylogeny isn’t useful for common ancestry past a certain level, which we generally call a “kind” (e.g. the wolf-dog kind). When it comes to humans, either the race is from Adam & Eve, in which case it is fully human, or it isn’t from Adam & Eve, in which case it never was, didn’t become, and never will be human.
    When you look at the “intermediates” between ape and human, they can fairly easily be classified as fully-ape or fully-human. Evolutionists choose not to do so, of course, but there’s a fairly wide gulf between, for example, Homo Erectus (man) and Australopithecus (ape). See also Neanderthals.

  13. 13
    wd400 says:

    How, from the data, do you know what the “level” at which phylogeny stops working is?

  14. 14
    wd400 says:

    To put it another way, why would a result imply ancestry when applied in a “kind” but not when applied between kinds, despite producing very similar results?

  15. 15
    Gordon Davisson says:

    I’d like to extend wd400’s question a bit: in “Chain Letters & Evolutionary History” (Scientific American, June 2003), Charles H. Bennett, Ming Li, and Bin Ma published a phylogenetic analysis of the evolutionary history of a chain letter (free copy here). They looked at a number of variants of the letter, and used mostly-standard techniques to infer their ancestry, which variations arose in what order, etc.

    Chain letters are, clearly, designed objects. Do you think there’s any reason phylogeny wouldn’t work on them?

  16. 16
    drc466 says:

    wd400,

    How, from the data, do you know what the “level” at which phylogeny stops working is?

    Short answer: You don’t, but just because you can’t precisely define where it stops working doesn’t mean that it never stops working.

    Longer answer: If you are looking for a bright red line that says “on this side, phylogeny implies ancestry, and on this side it does not”, obviously there isn’t one.

    The creationist view of molecular phylogenies isn’t very different from the evolutionist’s:

    Creationist: The stronger the similarity, the more likely the relationship exists.
    Evolutionist: The stronger the similarity, the more recent the relationship.

    The difference is that creationists believe the phylogeny stops indicating common ancestry at a certain point – the evolutionist doesn’t, and thinks the huge gaps in molecular comparisons are simply artifacts of extinct ancestor species.

    Besides that, creationists are not the only ones who believe that, at some point, phylogenies stop working. Take, for example, my previous example of hemoglobin-based genetic comparisons. Do you agree that crocodiles have a closer common ancestor to chickens than their fellow reptiles, the vipers? I’m going to assume your answer is “No” – in this case, the molecular phylogeny is misleading – it “stops working”. Yet, as an evolutionist, you obviously believe that molecular phylogenies do provide evidence for universal common ancestry. This puts you in the exact same position I’m in – molecular phylogenies can be a helpful tool (wolves and dogs both have 78 chromosomes – may imply common ancestry, or “kind”), but sometimes it “stops working” and we need to rely on other information (dolphins and rabbits both have 44 chromosomes – probably doesn’t imply common ancestry).

  17. 17
    wd400 says:

    Well, there doesn’t have to be a bright-white line, but there should be something in the data that tells you it starts getting unreliable. You are welcome to belive in created kinds, but it seems very unscientific to believe a method works within kinds and arbitrarily dismiss the same results when they are applied between kinds.

    As to the rest of your comments. Phylogeny is about much more that similarity — at it’s hard it’s a model of how characters change. And evolutionary biologists ceratainly agree there are situations in which phylogeny is inaccurate, but we have learned about those scenarios through studying data, performing simulations and doing math not resorting to an arbtrary cut off.

    I certainly do agree that corcodiles an d chickens share a more recent common ancestor that either does to snakes lizards and the like. Birds are dinosaurs therefore the closest living relatives to crocs and aligators, this is not constroversial among scientists. As I mention, there are other specific cases in which a molecular phylogeny is misleading, but we understand those.

  18. 18
    Joe says:

    wd400- It isn’t arbitrary if what makes an organism what it is is something other than the organism’s genome. When applied between Kinds it would show the degree of common design used. And from there we may be able to determine the original design all of those were based on.

  19. 19
    Joe says:

    wd400:

    Were the various human populations around the world separately designed? How about neanderthals and modern humans? How would you tell the difference?

    It would all depend on the information required to produce what we now observe. I have always been a populations guy as opposed to just two people. However I also understand that it may be possible for two people to carry enough information to create the races we now observe. It all depends on what is required.

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