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Biotech Science

Ape-Human Split Moved Back By Millions Of Years 390

Posted by kdawson from the everything-you-know-is-wrong-again dept.
E++99 writes in to let us know about a development in paleo-anthropology. It seems that up until now, scientific consensus has placed the divergence of man from the ape line five to six million years ago (based on "genetic distances"). But newly discovered fossils in Ethiopia place the divergence at least twice as far back, and perhaps as long ago as 20 million years. They also largely put to rest any doubts that man and modern apes both emerged from Africa. From the article: "The trail in the hunt for physical evidence of our human ancestors goes cold some six or seven million years ago... Beyond that... fossils of early humans from the Miocene period, 23 to five million years ago, disappear. Fossils of early apes especially during the critical period of 14 to eight million years ago were virtually non-existent — until now... [T]he new fossils, dubbed 'Chororapithecus abyssinicus' by the team of Japanese and Ethiopian paleo-anthropologists who found them, place the early ancestors of the modern day gorilla 10 to 10.5 million years in the past, suggesting that the human-ape split occurred before that."
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Ape-Human Split Moved Back By Millions Of Years More

Ape-Human Split Moved Back By Millions Of Years

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  • How very fitting (Score:5, Funny)

    by d3vo1d ( 607758 ) on Saturday August 25, 2007 @04:38PM (#20356653)
    that this comes right after the story entitled "Attack of the Evil Monkeys From Hell".

    • Re: (Score:2, Funny)

      by Samah ( 729132 )
      You're forgetting of course that we all split from the Peanuttius Butria [youtube.com] gene millions of years ago.

      • Re: (Score:2, Insightful)

        by Loconut1389 ( 455297 )
        im stupider for having watched that, they even made me use the 'word' 'stupider'. That said, I'm actually glad to know that people are being subjected to that kinh of logical fallacy. I make no suggestions as to how life did or didn't start- evolution or not, our existence is a paradox, but if you're going to try and change beliefs, at least try not to intentionally mangle logic and reason.

  • Creationists Declare Evolution Disproved (Score:3, Funny)

    by Anonymous Coward on Sunday August 26, 2007 @01:38AM (#20359885)
    in 5... 4... 3...

    • Re: (Score:2, Insightful)

      by Smight ( 1099639 )
      I think the bigger target is "scientific consensus."
    • Actually, this puzzles me.

      It's the timeline.

      Dinosaurs die out about about 85 million years ago, right?
      And at that time mammals were represented by a creature about the size of a small dog - is that right?
      So in 85 million years we got from one small species to many species of various sizes - but it took a quarter of that time to get from chimp to human? This doesn't sound right to me.

      What am I missing here?

      • Re: (Score:3, Informative)

        by Anonymous Coward
        Actually, mammals appeared more or less at the same time dinosaurs did. It's just their success came after dinosaurs vanished. There were many species of mammals contemporary to dinosaurs.

      • Easy... it's pretty butchered and you're wrong. (Score:5, Informative)

        by Tatarize ( 682683 ) on Sunday August 26, 2007 @07:50AM (#20361431) Homepage
        Dinosaurs died out 65 million years ago at the KT boundary.

        Prior to that time the mammal line had already split much more than we previously gave it credit for, a lot of the main groups were developed. This article is a fairly worthless crock. Basically some teeth were found that looked vaguely gorilla like and dated back 10 million years. So we know that there was some ape-like creature with a gorilla-like diet 10 million years ago. However, saying that this is the Ape-Human split is as stupid as saying it's the Human-Mammal split. Humans are apes. We are clearly within the same grouping of gorillas, orangutans, and chimps. There's no real grouping of animals which includes those yet excludes humans. This find perhaps sets back the date of chimp-gorilla split but not "human-ape". That's just stupid. Chimp-human is a split which dates back about 4-6 million years. Gorilla-chimp goes back 8 million years, though perhaps 10 if this isn't just some offshoot.

        Finally, 10 million years is about 2/17th of 85 million years. Basically your math is off, and you're using old information, and to top it off this article is totally stupid. It's 10 million year old gorilla-like teeth. It actually has almost nothing to do with human evolution, though if you studied gorilla evolution you might care. Though, it's even weak evidence that it's actually a gorilla just that it had a diet like that of a gorilla.
      • While evolution is the change/creation of a species due to gradual change over multiple generations, if there is a drastic change in the environment, that change can occur quite fast. Check out Stephen Jay Gould's work on Punctuated Equilibrium. It helps explain also why it's difficult to find transitional fossils.

      • Re: (Score:2)

        by cnettel ( 836611 )
        The major lines of mammals were already in existence long before the dinosaur extinction (65 mya). None of them were too large, but if the fossil record teaches us anything, changes in size can come on quite fast.

        • Re: (Score:3, Insightful)

          by vhogemann ( 797994 )
          Fossil record?

          Heck, look at the variety of dog races we have! Allmost all of them were created by man using selective breed... In only a few thousand years we come from a wild wolf to a punny chiuaua!

          How "inteligent design" folks can deny this evidence?

          • Re: (Score:3, Insightful)

            by TempeTerra ( 83076 )
            Indeed. The more sophisticated ID arguments acknowledge evolution within species (dogs, for instance), but argue that evolution alone couldn't have produced different species, or the range or species we see in the world given the age of the earth (even if they're not sticking to 6000 years ;)

            It's the kind of argument that works well against the man-on-the-street, who hasn't heard of things like ring species [wikipedia.org], so there's a heads up for you :)

            One of my pet peeves is people who 'don't believe in evolution'. Evo

      • The rate of phenotypic change isn't constant. (Score:5, Informative)

        by Grendel Drago ( 41496 ) on Sunday August 26, 2007 @09:17AM (#20361845) Homepage
        As someone else pointed out, the KT boundary was 65 Mya, not 85. Also, early mammals of that era are usually described as "shrew-like" (also nocturnal, which is why we all have different color vision systems than reptiles), so probably even smaller than that.

        The line that would eventually give rise to the mammals split from the reptile lineage before the emergency of the dinosaurs (the number cited is 324 Mya); look up "synapsid" for more information. It was actually the dominant type of land fauna until the greatest mass extinction in history at the end of the Permian (250 Mya), which was followed by the emergence of the dinosaurs. There were large synapsids in the early years of the Mesozoic, but the branch that would give rise to the mammals--the cynodonts--emerged about 220 Mya. There's a rather exhaustive description over at Wikipedia [wikipedia.org]; also see talkorigins [talkorigins.org].

        On a more relevant note, consider the whales. It appears now that whales are more closely related to hippos than hippos are to cows. (Again, see Wikipedia [wikipedia.org] for a good summary.) This was mightily confusing, because we generally take phenotypic change as an indicator of distance between species. The important thing to remember here is that species change due to pressures put on them. Rapid pressures brought on by migration into a new environment (like the sea, for example) will cause a greater rate of phenotype change than would exist if the environment remained constant--consider the shark for this latter case.

        Also, as another commenter has pointed out, the mammalian lineages had already split at that point; divergence points for some groups of mammals are after the KT boundary, but many are before it. However, it appears that even though the groups were separate, they all looked pretty much alike until they migrated into the niches vacated by the dinosaurs and diverged widely.

        And lastly, your math isn't quite right. 7 million years (the divergence point for the chimp and human lineages, notwithstanding a very poorly written article) is more like a tenth of the time it took to get from (many kinds of!) shrew-like mammals to a similar level of mammalian diversity to what we see today.

    • Re: (Score:3, Insightful)

      by Loconut1389 ( 455297 )
      I personally don't lend much credence to creationism- but I don't see why they don't just say "ok, so we might have been a bit wrong about the timeline". After all, the bible was written by men (who are fallible, no matter what you think of God) in another language and then tranlated to english, a number of different ways. Ah, but therein lies the rub, if you accept that the bible isn't a 100% literal account of God's law, then much of the religion breaks down- especially for the more orthodox end of the sp

      • Re: (Score:3, Insightful)

        by tompaulco ( 629533 )
        I consider the creation event to have been explained to Moses in a way that he would understand it in the science of his day. I do not think it likely that it could have been a literal six days, although I guess a supreme being could do whatever he wanted including making stars with their light having already traveled thousands of light years along their paths to our eyes.
        However, it is my opinion that the reason literalists are so rigid is because of the non-believers. There are people out there who would

  • simpsons quote (Score:5, Insightful)

    by timmarhy ( 659436 ) on Sunday August 26, 2007 @01:44AM (#20359917)
    "Yet another example of science failing in light of overwhelming religous evidence!"

    don't laugh too much... there's people out their who really think this way.

  • Implications on inter-ape relationships (Score:5, Insightful)

    by saforrest ( 184929 ) on Sunday August 26, 2007 @01:46AM (#20359927) Journal
    Hmm, the immediate implications here seem to be mostly for our relationship with orangutans and chimps, and less so for our chimp relatedness. If true, this gives us a lower bound on the number of years since the divergence between the human/chimp line and the gorilla line, but we still don't know when we diverged from chimps.

    I expect they will adjust the molecular clocks to reflect the new knowledge and make a new guess. But the lesson of this whole discovery is that the current models for molecular clocks seem to be a bit lacking.
    • Hmm, the immediate implications here seem to be mostly for our relationship with orangutans and chimps,

      Gah, that should read "orangutans and gorillas,".

    • I expect they will adjust the molecular clocks to reflect the new knowledge and make a new guess. But the lesson of this whole discovery is that the current models for molecular clocks seem to be a bit lacking.

      hold on a second, we need to look into things a bit more first. first thing to do is to check the ancestral lineage for these species, there should be a clear line of species between us, the primates and these species. if these species really are ancestral species at this age we need to find out wh

    • Re: (Score:2)

      by E++99 ( 880734 )

      I expect they will adjust the molecular clocks to reflect the new knowledge and make a new guess. But the lesson of this whole discovery is that the current models for molecular clocks seem to be a bit lacking.

      I suspect so. However, IANA Molecular Biologist, but seeing how some species (like cockroaches, and probably many species of bacteria) go virtually unchanged for hundreds of millions of years, while other species (like humans) seem to undergo relatively drastic changes in some very tight timeframes,

      • Re: (Score:2)

        by Rakishi ( 759894 )
        As I understand it molecular clocks are usually based around junk dna, in other words dna whose change does not affect the creature. This is in contrast to genes which when changed can significantly alter the creature.

        • Re: (Score:3, Interesting)

          by jafiwam ( 310805 )

          As I understand it molecular clocks are usually based around junk dna, in other words dna whose change does not affect the creature. This is in contrast to genes which when changed can significantly alter the creature.

          Which assumes "junk DNA" is doing nothing (and there are some hints that it is doing something).

          And that a drift with NO control whatsoever never has stagnant times or changing times. (Natural radiation varies from place to place so if one group of life ends up dominant from the low area, the clock is different than if it was from a higher mutation area. Same concept with viruses and whatnot, lots of the "junk DNA" appears to be genes of old micro-organisms that worked their way in to replicate with the h

      • Re: (Score:2)

        by arth1 ( 260657 )
        What you fail to take into account is that many species have much more inert genetic material, i.e. more base pairs in their DNA that don't encode for anything. And when changes happen there, nothing happens to the species. In addition, much of what is left might be "critical" genes that can't be changed without causing inviable individuals.
        Finally, the very amount of DNA that can be altered also matters -- number of chromosomes and their length.
        So the outwards observable effects are limited to those DNA
  • breeders?

  • Misleading to talk about a "human-ape split" (Score:5, Insightful)

    by tirerim ( 1108567 ) on Sunday August 26, 2007 @01:50AM (#20359955)
    Last I checked [wikipedia.org], "apes" were actually paraphyletic—that is, humans and chimpanzees actually forma a clade, and gorillas split off some time earlier (and orangutans before that, and gibbons even before that). So it should really say that the split between gorillas and Hominini (chimps and humans) was earlier than previously thought. The discovery gives no information at all about when humans and chimpanzees split.

    • Re: (Score:2)

      by catbutt ( 469582 )
      My understanding of the article is that they are indeed talking about the human chimp split....but it is weird and confusing that they keep talking about gorillas....since as you say they split from the chimp/human line long before the chimp/human line split into chimps and humans.

      Talking about a "split" is confusing anyway, what they should be talking about is when the most recent common ancestor of modern apes (presumably chimps) and humans was.

    • Re:Misleading to talk about a "human-ape split" (Score:5, Informative)

      by j01123 ( 1147715 ) on Sunday August 26, 2007 @03:49AM (#20360545)
      Apes are monophyletic [wikipedia.org], because apes include humans. You are correct though, that the non-human apes are paraphyletic, because the closest living relative of the chimps are humans.

      My impression of the Nature article [nature.com] (subscription required) is that the authors are claiming that their paleontologic find pushes the gorilla split (from the human-chimp lineage) back to ~12 million years. Based on this, they essentially recalibrate the molecular clock as it relates to several of the ape divergences. This information is in section 5 of the paper's online supplementary materials [nature.com] (subscription not required), not the body of the article. Keep in mind that supplementary materials generally aren't peer-reviewed as rigorously as the rest of the article.

      • Re: (Score:3, Informative)

        by catbutt ( 469582 )

        Apes are monophyletic, because apes include humans
        I think more accurate would be to say "Apes are monophyletic, if you consider that apes include humans". Most people don't consider them to include humans, anymore than they consider dinosaurs to include birds or reptiles to include mammals.

        However, Hominoidea, the "ape clade", certainly includes humans.
        • "Most people don't consider them to include humans."

          Anyone who knows what monophyletic and paraphyletic mean isn't "most people".

  • THOUSANDS OF YEARS AGO, before the dawn of man as (Score:2, Funny)

    by Anonymous Coward
    an ape-like creature making crude and pointless toys out of dinobones and his own waste, hurling them at chimp-like creatures with crinkled hands regardless of how they behaved the previous year. These so-called "toys" were buried as witches, and defecated upon, and hurled at predators when wakened by the searing grunts of children. It wasn't a holly jolly Christmas that year. For many were killed.
  • Comment removed based on user account deletion

  • Summary of the Article (Score:4, Insightful)

    by jpetts ( 208163 ) on Sunday August 26, 2007 @02:36AM (#20360161)
    "Towards the end of our research period we came across some fossil teeth that MAY be identified as coming from the after the split between gorilla and human ancestors.

    Not only that, they MAY be earlier than the previously proposed date for the gorilla an human split."

    ===========

    The fossil teeth demonstrate that the last common ancestor of the gorilla and human was "out of Africa" (although this has been disputed), it is not a point of real controversy.

    This whole article reeks of conditionals, and restatements of non-controversial theories (e.g. " There is broad agreement that chimpanzees were the last of the great apes to split from the evolutionary line leading to man, after gorillas and, even earlier, orangutans"), and there is nothing but speculation and weasel wording in the entire article.

    This is just grant-milking, and possibly -- though I hope not -- nationalism and nonsense of the worst kind. NOTHING reported in the linked article is substantive in any sense, and is not worthy of comment or rebuttal unless and until some real theorems are posited.

    Non-news. Pass it by.

    • Re: (Score:2, Informative)

      by E++99 ( 880734 )

      Towards the end of our research period we came across some fossil teeth that MAY be identified as coming from the after the split between gorilla and human ancestors.
      Not only that, they MAY be earlier than the previously proposed date for the gorilla an human split. ...
      This whole article reeks of conditionals

      They found fossil teeth. They identified them as coming from after the gorilla-human split. They dated them to 10.5 mya to 10.0 mya. Their colleges agreed. Using such conditionals is how responsible

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