The Australian Aborigines may not be just descendants of first settlers

By Razib Khan | September 22, 2011 5:52 pm

Just realized. The Science paper has some interesting dates which allows us to make the above inference.

- Separation between Europeans and East Asians 25-38 thousand years before present.

- Gene flow between proto-East Asians and proto-Australians before the Native Americans diverged from the former 15 thousand years before the present.

- A conservative first landing in Australia 40-45 thousand years before the present.

The Native American result, where they share some derived variants unique to East Eurasians (mutations which emerged after the separation from West Eurasians) with Aborigines, pegs a minimum date of admixture ~15,000 years ago. But, obviously the admixture had to occur after the divergence of West and East Eurasians. Let’s say ~30,000 years ago. Even assuming that the gene flow between East Eurasians and proto-Australians occurred immediately after the separation 38,000 ago, there were anatomically modern humans in Australia for thousands of years already! The implication is that the first Australians by necessity can not have contributed in totality the ancestry of modern Aborigines. The AJHG paper gives a 50:50 estimate for the ratio of proto-Australian and the Andaman Islander/Malaysian-Negrito related population. We don’t need to be certain of the exact value to assume that numbers like this imply considerable admixture above trace levels.

Of all the dates I’m probably most confident about the archaeological ones about the settlement of Australia by anatomically modern humans. 46,000 years ago the megafauna started going extinct. That’s an immediate tell that humans have been let into the garden.

  • Sandgroper

    Aside from the dubious Rottnest Island evidence, all of the dating confirms a first entry around then.

  • Justin Giancola

    inagaddadavida baby

  • http://o-song.tumblr.com/ Tim Byron

    What you’d want to have here for comparison is genetic material from Tasmanian aborigines, who – I get the impression – seemed to be a little separate genetically from the rest of the Australian indigenous population. Perhaps they never interbred with the Asian population? It’s very much a shame, though, that they were completely wiped out a century ago, by disease and white settlers (apart from some who interbred with whites).

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #3, i don’t think they’re going to be that different. but, there are people who are descents. in any case, there are samples you could get. the politics of it all. if the tasmanians don’t have it, that would be that the ocean separating tasmania 10,000 years ago blocked, so it blocked that. but i doubt it was that recent, the native americans share the same derived mutants.

  • http://entitledtoanopinion.wordpress.com TGGP

    I recall Keith Windschuttle arguing that there were multiple waves of “aboriginal” australians. I forget if that theory has been discussed here before.

  • Sandgroper

    Windschuttle is an historian, rather than anything else, and heavily politically motivated. It suits his purpose to argue for multiple waves. I’m just saying, it pays to regard both him and his activist political opponents with a suitable amount of skepticism – neither should be regarded as a ‘source’ on archaeological or genetic evidence.

    The most parsimonious explanation of the evidence from remains is a single wave.

    This paper would change that. The interesting question is whether it is indicating a second wave, or marginal contact. I can’t read the paper, but from the ratio quoted by Razib, it seems to be indicating the former rather than the latter.

  • Sandgroper

    TGGP – by ‘evidence from remains’ I mean osteological evidence, not genetic data. That’s the elephant in the room, of course – Australia is screaming out for, not just one or two samples, but north-south east-west + Tasmania, plus time depth.

  • SFReader

    Most aboriginal Australian languages belong to a single macro-family with not very deep genetic depth (about 10-12 thousand years before present)

    The implication is that the Aborigines are descendants of immigrants from Papua-New Guinea (which was linked to Australia during the Ice Age) who displaced (or maybe even ate) the original Aborigines.

  • SFReader

    Here is a striking map http://upload.wikimedia.org/wikipedia/commons/5/5a/Australian_languages.png

    As you can see, pretty much all of Australia is covered with members of the Pama-Nyungan family

    About the age of Proto-Pama-Nyungan

    “Proto-Pama–Nyungan may have been spoken as recently as about 5,000 years ago, much more recently than the 40,000 to 60,000 years Indigenous Australians are believed to have been inhabiting Australia. How the Pama–Nyungan languages spread over most of the continent and displaced any pre-Pama–Nyungan languages is uncertain”

    http://en.wikipedia.org/wiki/Proto-Pama%E2%80%93Nyungan_language

  • CoffeeCupContrails

    Didn’t some researchers (Harvard?) a couple of years ago, study the genomes of the Nicobarese natives in the Andaman and Nicobar islands in the Arabian sea?

    I’d like to know how this study could relate to that. Any connections here to those natives or the ancestral South Indians (Nicobarese and south indians being related?), supposed to have migrated into India tens of thousands of years ago.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #10, nicobarese are like southeast asians. the andaman islanders are the closest relatives of the ‘ancestral south indians.’ the two are very different groups.

    This paper would change that. The interesting question is whether it is indicating a second wave, or marginal contact. I can’t read the paper, but from the ratio quoted by Razib, it seems to be indicating the former rather than the latter.

    both papers indicate admixture between the ‘australian wave’ and an ‘east eurasian wave.’ the latter itself being a branch of the second out of africa wave in the latter paper. *if* the inferred dates of the separation of europeans and east asians are correct i can’t see how humans resident in australia 44,000 years ago had east asian admixture only, and not more general admixture from the second wave (since the second wave hadn’t differentiated). so either the date is wrong, or, there was at least one second wave of people. that second wave might themselves have been hybrids of east eurasians of wave 2 + proto-australian remnants in southeast asia. or, they may have been “pure” second wavers who landed in australia. on the other hand, if the dating of the separation of east asians and europeans is off (the whole mutation clock issue which *might* mean that you multiply all last common ancestor estimates by a factor of two), then you can save the australia-settled-by-one-wave model.

    i don’t know what to think. but i do think some connection between ancient southeast eurasians and proto-australians does neatly explain tentative phenotyic and genetic connectiosn which span south asia to australia. i’m not a phenotypic expert, but my impression also is that ‘australoid’ south asians are not nearly as robust as australian aborigines. this could be due to evolutionary change since their last common ancestor, which is probably on the order of 15-30 thousand years in the past. but, it could also be in part the fact that the robusticity of aborigines derives from their proto-australian forebears.

  • http://genealogyreligion.net/ Cris

    I am not so sure that megafauna extinctions are well correlated with human arrival and hunting. David Meltzer, a Paleoindian archaeologist at SMU, has taken a hard look at this idea as applied to Amerindians, and finds the evidence sorely lacking. I think the article is called “Peopling of the Americas” and it refers to some Australian studies that also cast doubt on this popular idea. If you would like, I will dig up the article and send it along.

  • JakeKreol

    Does that mean, the first migration took place from africa, via India reached australia, then a second migration did that take place in africa or did that take place FROM south asia.

    Thats what puszzling me, if europe and central asia was populated from south asia, then surely after the first migrations out of africa, that spread rapidly to australia, the second migration must have taken place from south asia, which would have had human population left over from the first migration from africa to australia, no?

    is it fair to say , that the so called second migration, if it was at all, took place from south asia and not africa? Because the assertion in the article that the decendants of europeans where wandering africa or arabia is clearly wrong, or biased, their decendants clearly are of south asia origin. As a northern route out of north africa into central asia does not stand up.

    thanks if anyone can clear my query up :)

  • Insightful

    I am not so sure that megafauna extinctions are well correlated with human arrival and hunting. David Meltzer, a Paleoindian archaeologist at SMU, has taken a hard look at this idea as applied to Amerindians, and finds the evidence sorely lacking. I think the article is called “Peopling of the Americas” and it refers to some Australian studies that also cast doubt on this popular idea. If you would like, I will dig up the article and send it along.

    Cris, I agree with you. I think it was likely something to do with ‘climate-change’ that caused the megafauna extinctions…

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    I am not so sure that megafauna extinctions are well correlated with human arrival and hunting. David Meltzer, a Paleoindian archaeologist at SMU, has taken a hard look at this idea as applied to Amerindians, and finds the evidence sorely lacking. I think the article is called “Peopling of the Americas” and it refers to some Australian studies that also cast doubt on this popular idea. If you would like, I will dig up the article and send it along.

    don’t believe in the climate change proponents. if you accept their argument, that’s fine. i don’t care to argue about this.

  • Sandgroper

    #12 – Suggestion – be very suspicious of dodgy dating.

  • gcochran

    “Cris, I agree with you. I think it was likely something to do with ‘climate-change’ that caused the megafauna extinctions…”

    You’re wrong. Christ, we know this one six ways from Sunday. There were big ground sloths in the West Indies thousands of years after the extinctions on the mainland. Am I supposed to think that the climate finally changed in the Caribbean just as humans settled the islands? Same for Wrangel Island, same for St. Paul’s island: mammoths survived for thousands of years after the mainland extinction – because nobody went there.
    Same for the Steller’s sea cow in the Komandorsky islands.

    Australia. The Americas. Madagascar. New Zealand. Mediterranean islands. The moment humans landed in a virgin land- one in which the hand of man has never set foot – the megafauna give up the ghost.

  • Sandgroper

    Australia twice – once on the mainland, and again when Tasmania became accessible.

  • IrfanKasim

    First migration from africa to australia, and a second migration from south asia to europe?

  • http://washparkprophet.blogspot.com ohwilleke

    IIRC, the linguistic picture of Australian aborigines and to some extent their genetics is a bit more complex than #9 suggests which a map can obscure because the north central coast of Australia has much higher population density than the outback. Basically, there is linguistic diversity and even some genetic diversity, but it is largely confined to the north central coast. The dingo which can be dated pretty definitively establishes a moment of contact which could have been an isolated episode, but at least by the era of the Austronesians there were regular but very thin trade between Indonesia and the North Central coast aborigines.

    In terms of sample diversity, the key break should be not Tasmania and continental Australia, but North Central coast v. interior populations (particularly towards the SW).

    Also, the evidence tends to contradict strongly #8 or the reverse, settlement of Papua New Guinea from Australia. While Papuans and Australian Aborigines are an outgroup relative to other Asian populations the genetics suggests a shared common origin rather than one being a source for the other. Phylogenetically, the two populations are similar in age but substantially disjoint. They have unconnected branches of multiple phylogenetic lineage trees. The basal lineages that would connnect Papuans and Aborigines are pretty much absent from either population. There is also really not evidence of measurable admixture between the two populations post-45 kya.

  • Darkseid

    man, someone needs to do a simplified diagram or youtube vid that summarizes all the recent findings cuz im having a hard time keeping it all straight in my head. an updated history of human migration map. just a thought…

  • ben g

    I second that, Darkseid.

  • T. Kosmatka

    I wonder how Mungo Man’s abberant mt DNA might play into all this.

  • Sandgroper

    I think Thorne is aberrant, not LM3.

  • Gisele

    Mungo Man’s mtDNA sequence can not be classified because it is too short.

    Australian Aborigines have affinities with New Guineans but they also have mtDNA haplogroups which are not shared with them.

    At least one Tasmanian mtDNA sequence (Presser et al. 2002) would be classified as haplogroup S which belongs to the N group of haplogroups (like the ‘O’ sequence of the Australian from the recent study).

  • http://genealogyreligion.net/ Cris

    I wasn’t trying to argue anything about climate change and megafauna extinctions. I was simply pointing out that the dates and correlations are uncertain. Nearly all complex events, such as megafauna extinctions, have multi-causal explanations. We know there have massive megafauna extinctions multiple times since the Eocene, and most of them weren’t caused by humans. I certainly didn’t mean to get anyone’s panties all in a wad over the issue.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    I certainly didn’t mean to get anyone’s panties all in a wad over the issue.

    don’t be an asshole about it yourself. and saying “Nearly all complex events, such as megafauna extinctions, have multi-causal explanations” is kind of a bullshit response, like wondering about sample size when you have nothing else to wonder about. it’s fine if you find the climate explanations plausible. i didn’t engage because your presuppositions have to be really different to even find this plausible IMO. and on your own blog you make plenty of clear and crisp assertions about human history which are easily problematized,* so i’m kind of skeptical of your “jeez, everything is so complex, let’s wait up” stance.

    * i actually disagree with a lot of your assertions, but my own views are so uncertain that i don’t think it’s useful to get into arguments when we have to work back to first assumptions.

  • http://lablemming.blogspot.com/ Lab Lemming

    Magee et al. (John, not me, and no relation) argued in their Geology paper that the climate change was caused by human induced deforestation and increase in burn rate, which weakened the north Australian Monsoon. It’s on my “to blog” list, so I can bump it up to the top of the queue if y’all like.

  • Sandgroper

    Yes, please, LL. I had it before and lost it, but recall the paper you are referring to. I have a suspicion now that the timing won’t fit, but need to review it. And it doesn’t work for Tasmania, but the megabeasties still went dead. Still…

    Thanks Gisele.

  • http://genealogyreligion.net/ Cris

    Wow — my allusion was about another comment entirely (the one which asserts with exasperated authority all the examples of human-caused extinctions and infers from this that all extinctions are so caused). I wasn’t aware that I had any presuppositions about this particular issue, and certainly don’t have any stake in these debates.

    As for assertions in my blog, it is of course a testing ground of sorts (and place for provocation) and if you’d like to come for some problematizing, you are most welcome.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    I wasn’t aware that I had any presuppositions about this particular issue, and certainly don’t have any stake in these debates.

    if you are going to throw around citations, it would be nice if you fleshed out your assessment. it is trivially easy to find an unrepresentative citation (though the one you gave isn’t really). that’s why i prodded you to be more clear in what you were getting at, instead of making vague assertions of complexity. i really don’t care if it’s complex, i’m curious as to why you think that the climate change hypothesis is so plausible. if you don’t care to spend your time explaining, that’s fine, but i’d rather not have discussion off on the tangent anyway.

  • http://genealogyreligion.net/ Cris

    I’m not sure why this comment string has acquired this tenor.

    I only mentioned the citation because it seems like the sort of study that might interest you and I seem to recall you mentioning somewhere that you didn’t have institutional access to some journal databases. I was simply offering to send it, in case you were interested and didn’t already have it.

    I never asserted anything about climate; someone else did after reading my admittedly tangential comment. If I recall, Meltzer doesn’t argue the issue one way or another (and neither do I); he just points out that the American megafauna extinction dates are sparse and spread out over several thousands of years, so correlating them with Amerindian hunting is difficult (or “complex”). I have read similar things about Australia, which is why I mentioned it.

    In any event, I hope this clears things up and all is now well.

  • Sandgroper

    It might have started when you responded to something Greg Cochran actually addressed to someone else.

    “I am not so sure that megafauna extinctions are well correlated with human arrival and hunting”

    Then I suggest that instead of repeatedly citing Meltzer like he’s the last word on the subject, you take a look at this, for example: http://www.pnas.org/content/105/34/12150.short In particular, I suggest you note the last sentence of the abstract and how that relates to what Greg said about islands and what I said about dating, instead of making cracks about his panties. I happen to know he doesn’t wear them.

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This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

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