One small step

[andrewducker]

The great leap is a Guardian article about the journey out of Africa and the change that happened in the species around that time.

By looking at a combination of clues from the human genome and archaeology we can trace two routes - one along the southern coast of Asia, which reached Australia around 50,000 years ago. Another route, inland via the Middle East, would lead to the settlement of Europe by around 35,000 years ago and to the Americas (via the Siberian arctic) 20,000 years later.

Fascinating stuff. Anyone recommend a good book on the subject?

Comments

[drainboy.livejournal.com]

How about these, seeing as they were at the bottom of the article ;)

Further reading

The Journey of Man: A Genetic Odyssey by Spencer Wells.
Penguin (2003). ISBN 0141008326
The Rise and Fall of the Third Chimpanzee by Jared Diamond.
Vintage (1992). ISBN 0099913801
The Dawn of Human Culture by Richard Klein and Blake Edgar.
John Wiley (2002). ISBN 0471252522
Molecular evolution of FOXP2 by Wolfgang Enard et al.
Nature 418: 869-872 (2002)
The evolutionary origin of complex features by Richard Lenski et al.
Nature 423: 139-144 (2003)


I do wonder where he got the figures of 2,000 people 60k years ago. How you could be so precise over that long a time is beyond me.

Mike

[kpollock.livejournal.com]

As I understand, by looking the DNA of modern humans and at the mutation rate.

There is less variation in human DNA across all people in the world (or at least the representative sample that we have tested) than there is in one small tribe of African chimps. If you take non-Africans (or people of recent african descent) it varies even less. This does seem to argue for a severe bottleneck at a point guessable by the mutation rate, and for an african 'origin'.

[drainboy.livejournal.com]

That's fine, the general results seem fine and vague enough to listen to as well understood to the depth of understanding we can manage after the fact.

But counting a population in the single figure thousands from 60k years later must, I presume, require almost as many made up numbers as Drake's Equation.

[kpollock.livejournal.com]

I can't really help, lacking the precise detail and training. I do know that there is controversy over the mutation rate, just to muddy it further.

I suspect that the actual research quotes a wide range figure with a large margin of error, but that sort of stuff never makes it into the summaries.

[kallah]

Actually, the Siberian arctic is an unlikely method of populating the Americas. The last research I saw on the subject suggested that the area had little in the way of game to attract anyone. Boats are considerably more likely, and would explain the population distribution better - archaelogical sites don't get younger the further south one travels.

[andrewducker]

From a (very) vague memory, I seem to recall that there were at least two lots of expansion over the top, with the Native Americans being the second wave that went over the top. The first wave may well not have gone that way though.

It would explain the fact that the South Americans seem quite different to the North Americans.