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Australia Earth Science

Australian Aboriginal DNA Suggests 70,000-Year History 228

brindafella writes with a link to an abstract at the journal Science that says "Scientists have obtained a DNA genomic sequence from a 100-year-old, voluntarily donated hair sample from a full-blood Australian Aboriginal man. [Analysis of the hair] shows 'Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. ... [Their] findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa.' A news story gives more detail."
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Australian Aboriginal DNA Suggests 70,000-Year History

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  • first... (Score:3, Funny)

    by chopsuei3 ( 517972 ) on Saturday September 24, 2011 @01:50AM (#37499778)
    out of africa!
  • by serbanp ( 139486 ) on Saturday September 24, 2011 @01:57AM (#37499792)

    It's interesting that 75ky is not enough time for a species to diverge into incompatible branches; successful mating between individuals from these branches creates perfectly normal offspring.

    I wonder what would have happened if the above was not true; probably even worse extermination, just like the bushmeat thing in Africa.

    • Actually it was about 45-50k years of isolation before other moderns got into Asia and you start to see an inflow of genes from other modern populations.

    • Re: (Score:3, Funny)

      by Anonymous Coward
      I for one am willing to admit that I have not had a successful mating with an Australian.
    • In all likelihood H. sapiens is adapted so well to different environments that there was simply not enough evolutionary pressure for speciation - we simply thrive everywhere as we are. Your speculation is interesting though, if real speciation happened there, how would we have handled it? Would make for a great SF story. If only I could write....
      • if real speciation happened there, how would we have handled it? Would make for a great SF story. If only I could write..

        It's been done to death; just a few examples, off the top of my head: van Vogt's "Slan"; Sturgeon's "More Than Human"; more recently, Nancy Kress's "Beggars in Spain". Not to mention the whole X-Men thing...

    • Re:evolution (Score:4, Interesting)

      by rgbatduke ( 1231380 ) <rgb@@@phy...duke...edu> on Saturday September 24, 2011 @07:36AM (#37500790) Homepage
      You mean like dogs can mate with wolves and foxes and create perfectly normal offspring? Or the way lions can mate with tigers? I thought at this point the notion that speciesization involved an inability to crossbreed with nearby branches and produced "normal", often fertile, offspring was passe'. Evolution is a lot more interesting than "just Darwin" these days, with the discovery that breeding across species is possible and even commonplace as well as the even more interesting discovery that a significant fraction (maybe 8%) of the human genome is viral DNA probably intercalated via retroviruses in a way that "stuck". It isn't all about simple single-site mutation and in-species crossover anymore (although natural selection itself survives, of course).

      However, your point is well taken -- as far as I know the aboriginal genome isn't sufficiently divergent to count as a separate species, any more than the pigmy genome. Or if they are, it's so uber-politically incorrect to point it out that nobody is doing so. OTOH, there was the recent discovery that one single bay in Australia is home to a unique species of porpoise that is genetically divergent enough to be considered separate (although I'd bet it is smoothly crossfertile with other Tursiops).

      rgb
      • You mean like dogs can mate with wolves and foxes and create perfectly normal offspring? Or the way lions can mate with tigers?

        Actually, this is quite wrong. While (to my understanding), dogs and wolves can create normal offspring, lions and tigers cannot. They do create offspring, called tigons and ligers, but they are anything but "normal", and are actually infertile. Ligers are giant animals, much larger than their parents, but IIRC have a lot of health problems as a result.

        It's sorta like donkeys and

  • 60,000-75,000 years is well before when many anthropologists believe we started using language and symbolic thought. Either they're wrong, or these developments were made independently across different isolated populations.

    • 60,000-75,000 years is well before when many anthropologists believe we started using language and symbolic thought. Either they're wrong, or these developments were made independently across different isolated populations.

      Personally I find those arguments specious. First, I'm not so sure language depends on "symbolic thought" -- or whether the concept is even well defined. Second, people have been saying since forever that the Neandertals were incapable of symbolic thought because of a lack of artwork and ritualistic elements with their funerals, but stuff has been turning up here and there for the last few decades, so much so that I don't see how anyone can hold that view anymore.

      I think there's a general tendency to see

    • Not any credible anthropologists. There's way too much data showing symbolic thought to be older than that (to the extent it is present in other species, and thus likely dates back to a common ancestor). As for language itself, there is no good data on when that started--some have tried to estimate it based on approximate rates of phonemic change and how far back you'd have to go for all known languages to coalesce, but that approach is based on extremely specious assumptions (among them that language was

    • You can't fault the Anthropologists for being extremely conservative with their view of human development and diaspora -- the sheer lack of information allows too much room for wild speculation and crack-pottery. Just look at those "Ancient Aliens" shows on the History Channel for a prime example.

    • There's at least some limited evidence of modern behaviors in Africa something around 70,000 years ago. You're a few decades out of date here. In particular see http://en.wikipedia.org/wiki/Klasies_River_Caves [wikipedia.org]

      I think timelines are still fuzzy enough to suggest that modern behaviors evolved in Africa itself.

      • Re:Wow (Score:4, Funny)

        by gilleain ( 1310105 ) on Saturday September 24, 2011 @05:19AM (#37500430)

        There's at least some limited evidence of modern behaviors in Africa something around 70,000 years ago. You're a few decades out of date here. In particular see http://en.wikipedia.org/wiki/Klasies_River_Caves [wikipedia.org]

        I think timelines are still fuzzy enough to suggest that modern behaviors evolved in Africa itself.

        Well surely you need _some_ kind of language to be able to say to a bunch of your friends : "Hey! Fancy going on a beach trip ... to Australia?".

        • Actually I think they only need to say just one world and that word could take them to Austrialia.

          The word being "Walkabout"

    • Re:Wow (Score:4, Interesting)

      by flyingsquid ( 813711 ) on Saturday September 24, 2011 @03:15AM (#37500024)
      60,000-75,000 years is well before when many anthropologists believe we started using language and symbolic thought. Either they're wrong, or these developments were made independently across different isolated populations.

      They're probably wrong. The evolutionary tree of Homo sapiens has four major branches: Aborigines, Eurasians, Africans, and Khoisan. The Aborigines and Eurasians are each other's closest relatives, Africans are more distantly related, and the Khoisan (bushmen) are the most ancient branch of our evolutionary tree. All four groups have the mental hardware to do things like use language, create artwork, and make sophisticated stone tools. While it's concievable that they each evolved that capability independently, Occam's razor says it's simpler to assume that it evolved once, than to assume it happened four separate times. And since Aborigines were around 70,000 years ago, this hardware package- what we'd called the "behaviorally modern" human- would have appeared by that time.

      Consistent with this idea, you get cave paintings in Australia around 50,000 years ago, as soon as the Aborigines show up there. And you get cave paintings and sophisticated stone tools in Europe around 30,000 years ago, when the Eurasians move out of Africa. In this scenario, the reason sophisticated stone tools and cave art don't show up earlier is that advanced humans were restricted to Africa. If so, then we would expect evidence for similar behavioral complexity- cave paintings, Neolithic-quality stone tools- in Africa prior to 70,000 years. My guess is that it almost certainly exists, but we just haven't looked in the right places (because it's a lot easier to do fieldwork in Europe than in Africa) or we've found it but haven't recognized it for what it is because the artifacts haven't been dated yet.

      • If so, then we would expect evidence for similar behavioral complexity- cave paintings, Neolithic-quality stone tools- in Africa prior to 70,000 years. My guess is that it almost certainly exists, but we just haven't looked in the right places (because it's a lot easier to do fieldwork in Europe than in Africa) or we've found it but haven't recognized it for what it is because the artifacts haven't been dated yet.

        Makes me wonder if the stress resulting from migration out of Africa prompted humans to develop new ways of communicating their condition. Painting may have been invented along the way because populations which had been confined to a small area in Africa now found themselves spread across the world. In a similar way modern humans who have migrated away from their home countries use the Internet to communicate with people with whom they share their condition.

        • Except we see the beginnings of symbolic thinking and other aspects of modern cognition in Africa first.

        • by jamesh ( 87723 )

          Or maybe they were just too busy surviving in Africa to take the time to paint lots of pictures?

      • The simple fact is that human evolution and that of our near relatives is a science that is undergoing rapid development. A lot of changes are bound to occur as new evidence forces a rethink of existing theory. That is good, stick to the same theory for to long and you are no better then a religious person.

        There are skeletons being discovered all the time that shows the old theories to be hopelessly wrong with a high probability that humans are not only much older but more cross linked then we thought.

        A rec

    • these developments were made independently across different isolated populations.

      Given how frequently parallel evolution has occured [wikipedia.org] in other areas, even in species vastly more diverse, why would that be surprising?

      • Mainly because there's a reasonable amount of evidence that the first signs of "modern" cognition are in southern Africa, and then seems to have been moved elsewhere as modern populations began spreading. This does not suggest a kind of multi-regional modern cognition hypothesis, but rather a singular point of genesis of such behaviors.

        • Mainly because there's a reasonable amount of evidence that the first signs of "modern" cognition are in southern Africa

          Wouldn't that, by its very nature, be simply evidence that shows signs of cognition and happens to be only found in southern Africa so far, rather than conclusively shown that cognition was only developed in Africa (and how would you even do that)? i.e. new evidence could easily disprove the theory -which may happen in this case, if other findings are correct?

          • There are other reasons that southern Africa is an attractive point of origin for modern H. sapiens. For one thing, it is the highest level of genetic diversity and certainly has the descendants of the oldest known modern H. sapiens populations. You are right that further discoveries could point to some other point of origin, and it's always possible that because there was always some gene flow that if the "modern cognition" genes evolved elsewhere, they could have made their way to southern Africa.

            That b

    • None of this can be correct. All of this evidence was left here by the devil to challenge our faith. For instance man was taught by the angels to talk. How could Adam or Eve be judged if they could not talk or have symbolic thoughts. Of course all the dates are wrong since there were only 75 generations of man between Adam and Jesus Christ(Luke chapter 3). There were 11 between Adam and Noah so humans and all the races and languages and migration developed in around 64 generations. This would be funny excep
    • > 60,000-75,000 years is well before when many anthropologists believe we started using language and symbolic thought. Either they're wrong ..

      They're wrong. There are tribes in Australia that have an ORAL HISTORY of 70,000+ years.

      Only stupid close-minded scientists/historians/anthropologists can't accept these developments of "human history" because it doesn't fit with preconceived ideas of what they THINK history _was. The hold onto their dogma because it means everything they "know" is WRONG.

      Science

  • those guys got to see jumping dinosaurs, that must have been awesome!

  • Lineage (Score:3, Insightful)

    by Zaldarr ( 2469168 ) on Saturday September 24, 2011 @01:58AM (#37499800) Homepage
    Great! Now if us Australians can stop treating them like second class citizens...
    • Re: (Score:2, Troll)

      by Psychotria ( 953670 )

      You might treat them as second class citizens. Your friends might. Your parents might. Our ancestors certainly did.

      I do not. Stop speaking for all of "us"; you just might find yourself in the minority.

    • They're citizens?
    • by Anonymous Coward

      Pffft! 70,000 years and what did they do with the place? Fuck-all.

      Didn't even get out of the stone age - and it's not for lack of resources in Australia, that's for sure.

      Now they're all, "respect our culture!". Sorry. Your culture was a dead-end and it was dead as a dodo as soon as Cook decided to claim Australia. I could possibly give some respect for their culture in the past tense, but the 'culture' I see day to day in my outback town - a never ending cycle of booze, disease and spouse/child abuse - is

  • The Cro Magnon man, aka the modern human, is considered to have appeared abotu 35 000 years ago.

    http://en.wikipedia.org/wiki/Cro-Magnon [wikipedia.org]

    Given the fact in the article, shouldn't we conclude the Australian aboriginals are, for instance, neanderthals by origin?

    • The Cro Magnon man, aka the modern human, is considered to have appeared abotu 35 000 years ago.

      Given the fact in the article, shouldn't we conclude the Australian aboriginals are, for instance, neanderthals by origin?

      Not really. The other option is to revise Cro-Magnon's "appearance".

    • Neanderthals were a separate branch, not a preceding one.

    • by MaskedSlacker ( 911878 ) on Saturday September 24, 2011 @02:46AM (#37499938)

      No. The evolution of the hominid family is WAY more complex than that. Basically you have a set of inter-breeding semi-distinct populations from 4 million years ago all the way to circa 30,000 years ago (maybe even as late as 20,000 years ago based on some finds of neanderthal tools). All the way through most of the populations would have been genetically similar enough to interbreed successfully (especially after H. ergaster and H. erectus 2 million years ago). H. heidelbergensis, neanderthalensis, and sapiens likely all interbred. Neanderthals were Europeans descendants of an earlier H. ergaster or H. heidelbergensis exodus from Africa. Australian aboriginals, like all modern humans, would be predominantly H. sapiens, with differing traces from the interbreeding with earlier populations.

      Moreover, you've misunderstood the data on the Cro Magnon man. Modern humans arrived in EUROPE (Cro-Magnon is the place in France where skeletons were found) 35,000 years ago (as best as we can tell). They appear in Africa almost 200,000 years ago, and in the Middle East before 60,000 years ago.

      • There's been a lot of recent news that modern humans in Europe and Asia interbred with Neandertals after they left Africa enough to show up in modern human genes (and some Asians interbred with other pre-modern humans over there), but that Africans who stayed in Africa didn't.

        So did these genetic studies look for Neandertal markers, and if so, what did they find?

    • Read your own link: "The Cro-Magnon were the first early modern humans (early Homo sapiens sapiens) of the European Upper Paleolithic." (emphasis mine)
      and further down:
      "Anatomically modern humans first emerged in East Africa, some 100 000 to 200 000 years ago."
    • Huh? No, they are morphologically modern humans. Anyone the least bit familiar with Neandertal and Modern skeletal structures can see where Aborigines fall.

      • Anyone the least bit familiar with Neandertal and Modern skeletal structures can see where Aborigines fall.

        Why do you need to be an archaeologist or anthropologist to stand outside a pub?

  • What stood out to me was that they found about 5% Denisovan [wikipedia.org] DNA. The latter being an early human that evolved independently from Homo erectus. This genome can also be found in some other Asian aboriginal populations but not modern day dominating populations such as the Han Chinese.

    This supports the theory of an early first migration wave out of Africa into Asia about 70,000 years ago that then encountered Denisovans and interbred. Thus there are two implications: Denisovan probably settled far further south

  • In a world where we actually hold televised events to find out who's the "baby's daddy", it's kind of cool that people can still trace back their linage like this.

"Protozoa are small, and bacteria are small, but viruses are smaller than the both put together."

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