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Old 09-24-2012, 06:13 AM
Blake Blake is offline
Join Date: Mar 2001
Posts: 11,049
Originally Posted by Shakester View Post
There are living full-blood Australian Aborigines,
Do yo have a reference for this claim? Because unless things have changed, no genealogist or geneticist makes such a claim.

"Mixed race" Aborigines made up over 50% of the continental population over 150 years ago. That fact alone makes it incredibly unlikely that anyone with 0% outside admixture could exist. It would have required deliberate efforts to avoid interbreeding, combined with an ability to trace genealogy to prove ancestry. Because the population was so small, without such efforts a single person with any outside ancestry sneaking into the gene pool more than 3 generation ago would pretty much guarantee outside ancestry within the past 200 years.

...and while they were never completely isolated from the rest of the world in the way that the Tasmanian sub-group were, they were mostly isolated from everyone except for near neighbours from their arrival in Australia at a very minimum of 40 000 years ago, and most likely 50 to 60 000 years ago.

So there's no way they have have a recent common ancestor with modern European/African/Asian populations. Anyone claiming they do is tripping. There is no way on Earth that they can possibly share an ancestor with modern Europeans any more recently than way over 40 000 years back.
Not only is there a way, it is almost certain that they share a common ancestor much more recently. Lets assume for a second that you can verify your claim of people with no recent outside ancestry. I'm not sure you understand how genetic dispersal works. Everyone on the planet was mostly isolated from everyone except for near neighbours from 40, 000 years ago until the past 50 years or so.

But that doesn't prevent genetic dispersal. If I marry a person from the village 50 miles to the west, then my children will share a common ancestor within 2 or 3 generations with everyone from that village. And if my child marries someone from the village 50 miles to the east, then there children will almost certainly share an ancestor within 2 or 3 generations with everyone within a hundred mile radius. And that is just two generations. Every two subsequent generation that radius will increase by 50 miles, meaning that within 400generations /8000 years someone in Ireland will be the ancestor of every single person in Europe and Asia.

Australians were no different. In fact the long trade routes and regular super-clan meetings where spouses were exchanged almost certainly lead to a relatively faster dispersal than Europe over the past 10, 000 years or so. While most farmers in Eurasia were living and dying within a few miles of where they were born. almost all Aborigines were meeting people from hundred of miles away many times during their lives. And at those meetings a few marriages almost always occurred. So every Australian would almost certainly have shared a common ancestor with every person living within 2, 000 kilometres within the past 4 generations, and with every other person on the continent within half a dozen generations.

Australia is about 4, 000 kilometres to a side. So if even one person each generation married someone who lived even 500 km away, and everyone else married someone from an area within 50 km, then every person on the continent would share a blood relative within 8 generations/160 years. Aboriginal populations were small, so common ancestry might lag that by 6 generations at most. So at the outside, all Aborigines "updated" their common ancestor every 300 years.

Once you combine that with the fact that Australians were in regular contact with Asia for at least 5, 000 years, and you will see why Australians can't be a significant outlier. As far as we can tell, 100% of Aborigines in The Top End have Indo-Malyan ancestry within the past 1,000 hundred years or so. But let's assume that even one of the IndoMalayans who brought dingoes to Australia, or one the continuous contacts since then, produced a surviving descendant in Australia. Just one single descendant any time in the past 5, 000 years of provable contact and trade, prior to 1712.

Given an ancestry mingling time of 300 years, a single descendant any time from the arrival of the dingo traders to the arrival of the Dutch would pretty much guarantee that Aborigines share the exact same common ancestry ass the rest of the Old World.

So if we accept that there is a recent common ancestor of IndoMalayans and the rest of the planet, then that must also be the ancestor of Aborigines. The only way that could fail to be true is if every IndoMalayn who interbred with an Australian came from a now extinct bloodline, which seems ridiculous.

Far from being no way on Earth that Aborigines could share a recent common ancestor with the rest of the Old World, it would take an extraordinary series of events for them not to share a common ancestor within the past few thousand years.