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Earth Science

1.8 Million-Year-Old Skull Suggests Three Early Human Species Were One 168

Posted by timothy
from the sounds-like-beatles-lyrics dept.
ananyo writes "A 1.8 million-year-old human skull dramatically simplifies the textbook story of human evolution, suggesting what were thought to be three distinct species of early human (Homo habilis, Homo rudolfensis and Homo erectus) was just one. 'Skull 5', along with four other skulls from the same excavation site at Dmanisi, Georgia, also shows that early humans were as physically diverse as we are today (paper abstract)."
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1.8 Million-Year-Old Skull Suggests Three Early Human Species Were One

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  • by Anonymous Coward on Saturday October 19, 2013 @05:40AM (#45173399)

    What! Science says that there were three different species of humans, now it says that there was only one. See. Scientists keep changing their mind. How could you put your faith in them? Put your faith in Jesus, God and read the bible instead. The truth in bible doesn't change over time, unlike science. Creationism triumphs over evolution once again.

    • Re: (Score:2, Flamebait)

      by Chemisor (97276)

      > Put your faith in Jesus

      You mean put your faith in God who is both one and three at the same time? It seems this finding can disprove your entire religion.

    • by mysidia (191772)

      What! Science says that there were three different species of humans, now it says that there was only one. See. Scientists keep changing their mind. How could you put your faith in them?

      Science evolves, based on the results of new experiments, and the acquisition of new information.

      Religious doctrine on the other hand; always stays the same, even when factual information proves something wrong.

      For example: it was proven that the earth and other planets revolve around the sun.

      Put your faith in Je

    • by flyneye (84093)

      uh-hmrm. I was just scrolling by, minding my own business; when I saw your little faux passe about the truth in the Bible not changing over time.
      Apparently , you never knew any of the controversy over the ages of translation mistakes, both accidental and political, the entire Septuagint rewritten from memory by Ezra while whacked out of his skull on the ancient "cup of fire" entheogen tea. The whittling down of the 600 or so books by the Catholic church for oftimes whimsical and political reasons to establi

      • by Empiric (675968)
        I was just scrolling by, minding my own business; when I saw your little faux passe about the truth in the Bible not changing over time.

        You actually didn't address his statement at all. While it's fun to talk about how many books there were, and how many changes there may have been, it actually doesn't make any more difference to the truth of the content than book editions today, or how many may be rejected by a publisher covering the same topic. Far from "whimsical", the criteria, determined at absolu
        • by flyneye (84093)

          Actually I did. Reread it.
          I didn't address your concerns at all.
          When the criteria starts out " There are four winds and four corners of the earth so there shall be four gospels" it starts whimsical and stays that way. The only serious part of it is that changes were made for political control reasons. Oh , I suppose you can listen to "divine" excuses all day and believe them if you have limited capacity like the majority, but a spade is still a spade and the self proclaimed Catholic organization is a sham.

          • by Empiric (675968)
            So, still no plausible combination of proposed scriptural change and actual political advantage that would be offered by it. You could have at least parroted some Dan Brown, even if that would put us at laughable levels of historical scholarship.

            The rest of your post is all over the map, lots of insults and very little useful content, but to answer what you appear to be staking out as your main relevant counterpoint, on "clean foods"...

            Here's a straightforward rationale found with a simple google searc
            • by flyneye (84093)

              When you eliminate other schools of thought by violence and ignorance in order that your school of though prevail, what about that doesn't appear to be a political advantage?
              If you don't like crap, relevant to the discussion pointed out, tipetoe through the pasture to the sister-boy forum where you can feel secure. If it happened and lends cause or effect as illustration, so be it. If it was to be historical record, they should've done something ethical instead. If you are insulted, were you involved someh

              • by Empiric (675968)

                More thinking, less trolling, if you are capable of it. You're stuck like a broken parrot on the notion of "political manipulation" (and now, that you have been shown to have no basis for your claim, you just desperately rhetorically amplify it with equally-unbacked "violence"), when there is simply no basis for it being relevant, when it could be actually relevant to your argument, before 200 AD.

                I don't rely on others. Stop with this ludicrous "all positions are somebody's, therefore whenever I feel like

                • by flyneye (84093)

                  Do you actually know anything about the subject or are you merely pissing into the wind?
                  Study the subject, then come back and pretend you know what you're talking about.

                  My method questions all who came before me and many are found lacking. Not unlike other sciences.
                  I will either take or dismiss the findings that came before on merit of credibility.
                  I operate from a meta-view crossing disciplines and arts and you come to me with your pathetic genetic fallacy of rational.
                  Don't make excuses for not keeping up.
                  I

                  • by Empiric (675968)

                    Yes, I know more than you about this, and every related subject. You need to take your poseur ego panhandling elsewhere. You have generated nothing but useless conceptual junk with your "meta-view" method, and neither have nor can present any concerted view with actual useful content. "Not that" is not a position, it is not an accomplishment, it is literally nothing--for another basic logical fallacy among the many you need to have a clue about to achieve the basic abilities at thinking you currently la

                    • by flyneye (84093)

                      Forgive me if I doubt you, for you appear full of shit. It detracts from your credibility. Anything you've presented is so pedestrian as to be recited by middle school logic students, as if logic were a course there. Did T.G. Seuss actually write the book you've studied?
                      My method, time tested and true has made my part of my fortune in everything from Archaeology to consulting. No one has ever complained at my lectures. The rest are military contracts and unrelated.

                      All rig

  • Here'e the problem (Score:3, Insightful)

    by jbmartin6 (1232050) on Saturday October 19, 2013 @05:47AM (#45173411)
    A nice example of the problems with using a point in time technique like taxonomy and applying it to an extended period of time. There's no single point where one species transforms into another, this is a very slow process. Any given sample, depending on where it is on the timeline, could belong to two different species. All the homo this and homo that is pretty much a waste of time, or so it seems to me.
    • by G3ckoG33k (647276) on Saturday October 19, 2013 @06:16AM (#45173483)

      It is not exactly like that. It is rather that any given sample along one line, regardless where it is on the timeline, belongs to only one and the same species, regardless of evolutionary change! A new species is _only_ formed when one line is split into two lines. And even more surprising, to many, then is that neither is the same species as their ancestor, for solely technical reasons.

      • by jbmartin6 (1232050) on Saturday October 19, 2013 @06:37AM (#45173513)
        You are correct, I think I should have clarified by saying that the point on the timeline where a new species is formed is entirely arbitrary, and an individual at that point is wholly compatible with some number of generations to either side.
        • by brunes69 (86786) <<gro.daetsriek> <ta> <todhsals>> on Saturday October 19, 2013 @07:51AM (#45173657) Homepage

          The true definition of species is a group that can and do inter-breed to make offspring. So, the line actually *IS* very clear cut... as soon as a mutation occurs that branches one set so they can no longer reproduce with the other, it is a new species. The problem is, determining that point in history using only archeology is very difficult and full of guesswork. Even if you have the DNA from all 3 sides of the tree, we aren't adept enough yet to be able to look at two pieces of DNA and say "yes these two could reproduce and make viable offspring", vs. "yes these two could reproduce but their offspring would all be sterile". That is when you form a new species.

          • Offspring of a mule (Score:4, Informative)

            by gd2shoe (747932) on Saturday October 19, 2013 @08:33AM (#45173755) Journal

            We like to think that it's clear-cut. When it's not, we quibble over just how to redefine "clear-cut".

            http://en.wikipedia.org/wiki/Mule#Fertility

            It seems we may be at the very tail end of Horse/Donkey differentiation.

            (Yes this is an assumption on my part, but I doubt there's good reason to think otherwise. A case to demonstrate this for more than two generations is probably too statistically unlikely to ask for. It might conceivably be possible to get Donkey genes into the Horse population with a couple of really lucky generations. IANAG)

            • by brunes69 (86786)

              I don't see how this contradicts the traditional definition of a species. Mules are infertile. Therefore they would not survive as a species in the first place if it were not for human breeders. They would just be essentially one-offs that happened occasionally in the wild, and die off. This is how evolution works; the mule would not be a successful species evolutionarily speaking.

              • by gd2shoe (747932)

                You didn't read the link, did you. Some female mules are not infertile. It's just incredibly rare.

                If a fertile female mule mated with a horse and produced a fertile female offspring, it could lead to convergence between one donkey and the horse population. Even assuming I know what I'm talking about (I've made a number of genetic assumptions), the odds of this are extraordinarily unlikely... but baring a particularly good reason why not, it is technically possible. Saying that it doesn't work because th

          • The true definition of species is a group that can and do inter-breed to make offspring.

            It's not as simple as that.

            So, the line actually *IS* very clear cut... as soon as a mutation occurs that branches one set so they can no longer reproduce with the other, it is a new species.

            What mechanism do you propose for causing the same (or at least compatible) changes in all the group at the same time? It's pretty unlikely to happen by chance.

            • by brunes69 (86786)

              Normally what causes the group to become differentiated is not a matter of "all at the same time". Groups become differentiated because they stop cross-breeding outside the group, due to either environmental or social barriers. Over time, these isolated groups develop their own mutations that are specific to them. And over an even longer period of time, they would not be able to reproduce with animals in the other group. It's no different than the process that resulted in humans evolving different feature s

              • by Shavano (2541114)

                and if we migrate to other planets, we will.

              • Which is completely *not* what you wrote before.

                Also, your definition would make lions and tigers the same species. Even if you added "... that can reproduce", it doesn't allow for oddities like ring species.

          • by mysidia (191772)

            The true definition of species is a group that can and do inter-breed to make offspring. So, the line actually *IS* very clear cut... as soon as a mutation occurs that branches one set so they can no longer reproduce with the other, it is a new species.

            That's one form of speciation. Another form, is some of the species settle in a different region --- with a very larger distance between two groups of the same species, they will become a different species, because they don't interbreed: even if t

            • by Shavano (2541114)

              By that definition, every isolated population immediately becomes a new species. The housecats of the Isle of Man, for instance, would be a unique species because without humans to transport them to England or Scotland, they can't interbreed with Irish or British housecats. Do you make an exception because housecats and other domesticated species have tricked humans into helping them spread their genes? How isolated does the population have to be? Were American Indians a separate species from Frenchmen

          • That is not the true definition of species. Wolves and coyotes can interbreed, but are still considered two different species by almost all taxonomists. At the same time Great Danes and Chihuahuas cannot directly interbreed, and yet are both simply considered subspecies of C. lupis.

            The notion of "species" is largely a human construct; an idea of convenience. Once you get to the Genus level, things start getting very muddied.

          • by Shavano (2541114)

            It's not as clear cut as all that either. When you take two populations that have been separated for a long time, they may be fully interfertile or they may have various degrees of ferility. For instance, horses and donkeys can have crosses (mules or more rarely hinnies) and sometimes female mules are fertile. Dogs are are still fully interfertile with wolves, but they have different physical and behavioral (esp. breeding) characteristics. They're also interfertile to some degree with coyotes, but those

          • yes, that is my point. It is perfectly clear when taken at a single point in time. It is not clear at all if you are dealing with a series of individuals over a (evolutionarily significant) length of time. Say, for example, that individuals can interbreed with any ancestor or descendant at +/- 50 generations. Outside of that range, genetic drift is too severe to permit interbreeding. So an individual at -30 gens can breed with one at generation 0, and can also breed with one at -70 generations. But the indi
          • by jamesh (87723)

            The true definition of species is a group that can and do inter-breed to make offspring. So, the line actually *IS* very clear cut... as soon as a mutation occurs that branches one set so they can no longer reproduce with the other, it is a new species.

            Suppose you have a string of islands, call them A-E. Birds on adjacent +2 islands can interbreed with fertile offspring, but birds at either end of the string of islands cannot. By the standard definition you can argue that the birds living on A are a different species to the birds living on E, but birds on A and E can breed with C, so the birds living on C must therefore belong to both species.

            Just because you have a clear cut _definition_, doesn't mean that applying that definition will get you clear cut

      • by TapeCutter (624760) on Saturday October 19, 2013 @08:23AM (#45173731) Journal

        A new species is _only_ formed when one line is split into two lines.

        Yes, but pinpointing the "split", is quite a problem [wikipedia.org]. You don't need fossils to show this 'problem', it can be seen in what are known as "ring species" that are alive today.

        Basically one species spreads both directions along a circular geological boundary. Despite the fact that all individuals along the expanding route can breed with the different races on either side of them, when the two expanding ends of the population meet at the other side of the boundary, they have become distinct species that can no longer interbreed. There is no point along the genetic line where the species forked, yet fork they did since each "end" of the route is a different species.

        Another more linear example (like the fossil record) are the changes that occur as a species expands it's range up a tall mountain, there's a continuum of slight genetic variations from the species at the bottom of the mountain to the (different) species at the top. Again, there is no point on the genetic continuum where it can be said the species "split".

        • The issues is also whether there is in fact any split at all. So far as we know, there have been damned few hominid species who have been truly isolated. Gene flow may have been fairly small, but it seems likely that even with H. erectus in Eurasia, there must have been some small amount of gene flow. We even have some evidence from nuclear DNA studies that there was possibly interbreeding between Neandertals and Moderns. Where even a relatively low level of gene flow is maintained, there is a fairly good c

        • Kudos for these terrific examples of the idea I was trying to communicate!
      • I don't agree with this at all. Even where a population never diverges, almost certainly speciation can and does occur, if you at least invoke simplistic (and obviously not entirely correct) notions like interfertility.

  • Simple (Score:2, Insightful)

    by symes (835608)

    Simpler is almost always better - and I for one am pleased to see our past more neatly explained. I worry about our willingness to complicate things in the name of science, sometimes.

  • Not sure I'd want all the text books to be re-written based on a single find. How do they know the skull5 wasn't due to some genetic defect?

    • Re:Maybe an anomaly (Score:5, Informative)

      by Patch86 (1465427) on Saturday October 19, 2013 @07:53AM (#45173663)

      That's pretty much the problem for the whole field. There are so few complete specimens (we're talking dozens, rather than hundreds) and they're generally so diverse geographically and chronologically that is becomes very difficult to say whether something was "species wide" or just individual variance. So you find a 4 foot tall skeleton on an island and you might be tempted to say "I've found a new miniature-species of human!", conveniently forgetting the fact that you only have one skeleton and dwarfism is a relatively common feature of the only human population we have a good sample of (modern us). That skeleton could have been the only 4 foot tall adult within a 100 mile and 100 year radius, and yet there's no way of telling unless you can find more specimens that agree or disagree. And those specimens may simply not exist to be found.

      I've always found fields like archaeology & palaeontology particularly fascinating for this reason. It's one of the few areas of science where there will be some things that simply CANNOT be known, because no evidence has survived of it and we can't ever study the past directly. It is one of the only areas of modern study where there is a real sense of mystery that will never and can never be lifted. Every little discovery we make is like finding a single piece of a 100 million piece jigsaw- you learn something, but the balance of things not known is still colossal.

      • by Alomex (148003)

        there is a real sense of mystery that will never and can never be lifted.

        Never is a very long time.

        I can go back to my childhood and make a long list of "we will never know" things that we know now, starting with the Titanic. I've read several books saying how we would never reach since it was at depths much beyond what divers and submersibles could reach, and in a span of ocean too vast to be effectively searched. Yet here we are, retrieving artifacts from the bottom of the sea.

        I can give many other examples.

        • by Patch86 (1465427)

          That's sort of my point. It's idiotic to say that we can never reach the bottom of the ocean- that's just an engineering problem. And while it's possible that it could be a "never" for humans travelling to other stars, never is indeed a very long time.

          But history is different. Barring time travel, if evidence for something hasn't survived, there is simply no way of knowing it. There might have been a really interesting species existing somewhere once with some really fascinating features and which could tel

          • by Alomex (148003)

            Barring time travel, if evidence for something hasn't survived, there is simply no way of knowing it.

            Correct, however how do you know if evidence didn't survive. Who in 1920 would have guessed we could reconstruct the main residence places of a person from mineral isotopes in the bones of said person?

            Similarly, want to know what language was spoken by the people of stone age Britain? Tough, you can't- they didn't write it down, and there is quite literally no way for you to know. Ever.

            The entire language likely not, but I bet already today we can use phylogenetic tools to identify some words that have survived from then until today. Once again who would have predicted 80 years ago that we could one day do analysis of this kind?

    • by Shavano (2541114)

      They don't. But what are the odds that of five individuals recovered from one location, one of them would be a freak? Or the location could have been populated by several different species over a period of as much as 20,000 years. That is certainly long enough for it to have happened. But the simplest explanation is one species with skull variations in its population not much greater than what we see in modern humans.

  • by mrwolf007 (1116997) on Saturday October 19, 2013 @07:17AM (#45173575)

    Man, the real story here is the skull.

    It dont really care what it suggests, the mere fact it was talking is creepy...

  • by cripkd (709136) on Saturday October 19, 2013 @07:40AM (#45173635) Homepage
    I really have question and then it's not ironic or rethoric.
    How do scientists know, when it comes to any prehistoric animal or human skeleton, when an individual becomes to a new species, to some sort of missing link or just-split subspecies, and not just a slightly different individual belonging to a known species?
    I mean how do they know when a lightly larger bump on a skull is not normal variation and it's for sure a new species where all individuals will have that bump?
    What puzzles me is that we find like 0.00000000001 of all living individuals from that time and species and yet we know it's relevant.
    • Re: (Score:3, Insightful)

      by gd2shoe (747932)

      How do scientists know, when it comes to any prehistoric animal or human skeleton, when an individual becomes to a new species, to some sort of missing link or just-split subspecies, and not just a slightly different individual belonging to a known species?

      When it permits them to publish a paper.

      No, I'm serious. When I was in school, the best lecturer in the department was almost canned because the department didn't want to give him tenure. Their excuse? (among other things) He didn't publish enough.

      The

    • by evilviper (135110)

      How do scientists know, when it comes to any prehistoric animal or human skeleton, when an individual becomes to a new species, to some sort of missing link or just-split subspecies, and not just a slightly different individual belonging to a known species?

      The short answer is that there are standards, but this field is an imperfect science, and finds like this, as well as DNA testing do redefine species lines. But does it really matter? A few changes to the ultimate family tree, here and there, doesn't fu

    • by rasmusbr (2186518) on Saturday October 19, 2013 @09:37AM (#45173985)

      I think they look at the complete picture and make their best guess based on all the evidence that they have and the best models that they have. The species concept is also inherently fuzzy. I'm not a biologist, but I've been told it can be fairly hard to tell if two living organisms are of the same species or not. Obviously, we should not expect perfect certainty about individuals that died 2 million years ago.

      Scientists never really know anything, because knowing something with full certainty is an absurd idea. When it comes to the distant past our best hope is to be able to paint a rough picture. Of course, advances in chemistry and physics may make it possible to analyze fossils at the molecular and atomic level and find out all sorts of amazing things about them that were previously thought impossible, but even then the whole detailed picture will always elude science.

      Creationists love this, but the problem with biblical creationism and Islamic creationism is that if there was a global flood 4000 years ago there would still be a global flood today, because there is nowhere for the water to go. Also, the moon missions would have crashed into the firmament that holds the flood gates to the waters beyond when they orbited the moon since the moon is attached to the firmament. It's funny that there are grown men that hold on to early iron age beliefs about the cosmos...

      • by gl4ss (559668)

        man you can't really argue with creationists about the flood since they can say that god drank the water or threw the water into the sun.

        for further points, see my sig.

        as to how scientists make decisions if some skeleton with deformed legs is a new species or not.. they make educated guesses, based on how the joints are laid out etc. as such history - biological or cultural - tends not to be an exact science but best guess science.

    • Short answer... They don't, not directly anyways. What they do use is techniques like comparative anatomy to determine if a substantial morphological differentiation in existing closely related species similar to those found in fossils represent two different species. But really, the idea of species is somewhat a convenience even in extant populations.

    • by Shavano (2541114)

      The decide whether it's different enough. And they assume that most of the specimens they find are not freaks.

  • We have found distinct groups, and we have called they species.
    At the same time we know they could interbreed, and there was no reason why they would not intermingle at times.

    Just because they found a few bones that were in-between these species does not suggest anything like, "these species never existed".

  • Surprise (Score:4, Insightful)

    by PopeRatzo (965947) on Saturday October 19, 2013 @09:01AM (#45173875) Homepage Journal

    I never knew before reading Slashdot how many "tech nerds" really hate science.

    I wonder how many of them are angry because they couldn't cut it.

  • by fygment (444210) on Saturday October 19, 2013 @09:09AM (#45173899)

    5 skulls leading to pronouncements on the species and its evolution?!

    5 of several tens or hundreds of thousands is not statistically significant.

    This is why creationism can survive, because it at times makes as much sense as the extraordinary extrapolations tossed out by scientists.

    Make it right. Demand that the scientists also share possible margins of error (in this case HUGE).

    • Re: (Score:3, Insightful)

      by koan (80826)

      Science has a tendency to correct it's self, creationism does not, you see that's the trap of religion, in order to be valid it must remain unchanged.

      Because if you change it.... =)

      • by Empiric (675968)
        ... in order to be valid it must remain unchanged.

        No, it doesn't. It shares the same process of contextual application as... most every domain of human activity. Is the U.S. Constitution "valid"? Does the fact we now aren't talking about literal militias and muskets in applying it, invalidate the principles?

        Feel free to continue making up universally logically-impossible criteria and false definitions, such as the meaning of "faith", and wishfully projecting that onto religious practice, though. En
    • The article has a few quotes from opposing viewpoints essentially calling bullshit.
      Science will not change because of one data point or one opinion unless it is bulletproof, which almost never happens. The real problem is reporting, where data is simplified once for the reporter, again by the reporter, again by the headline, and probably once each by the editor and reader.
      Go read the article, note both sides being represented, and admit how you simplified one person's report to mean all of science, and come

    • by devent (1627873)

      If you think the margins of error are huge if you have like you claim "5 of several tens or hundreds of thousands" like in palaeontology, what kind of error margins have you if it is "0 of several tens or hundreds of thousands", like in Creationism, infinite?
      Because at least we have evidence in the faculty of palaeontology and in natural evolution, but none evidence for Creationism.

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