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#18167 02/16/07 02:18 AM
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I?m sorry. I couldn?t resist it. I?m still on holiday so have time on my hands. Hope this isn't too long. So drawing on my knowledge of evolution and genetics here?s my interpretation of where Adam and Eve came from and the routes their descendants? took as they spread around the world. I look forward to any criticism anyone is prepared to offer. The account is derived mostly from the information on diagrams and maps of the human Y-chromosome (male) and mtDNA (female) lines at these two sites:

http://www.scs.uiuc.edu/~mcdonald/WorldHaplogroupsMaps.pdf

http://en.wikipedia.org/wiki/Haplogroup

Unlike most researchers I will not automatically assume an ancient Moses led a group of modern humans out of Africa. I would remind you that expanding lines displace, or at least reduce, previous Y-chromosome and mtDNA lines in any region. Migrations are usually long, drawn-out processes though. Genes from earlier populations frequently survive. Modern Y-chromosome and mtDNA distribution is usually accepted as being a result of cultural and technological expansion. Perhaps we should assume the same was true for ancient movements, even as far back as Homo habilis times.

Of course we cannot automatically assume any ancient, or even modern, migrations always include both men and women. It isn?t only married men who migrate to new regions. For example in several South American groups virtually all the Y-chromosomes are European while the mtDNA is entirely from local indigenous people. Any man who travels a lot can spread his genes, including his Y-chromosome, quite widely. For many reasons women?s genes spread more slowly. The two lines can be remarkably independent.

The first thing to notice about the maps is that geographical extremities generally retain older lines. On the other hand the Iranian plateau and Central Asia have always been a main highway. A whole series of migrations have zipped through there and left descendants. Each new migration has lowered the proportion of pre-existing lines. When we turn to the family trees the first thing we notice is that although Adam and Eve both lived in Africa there is a gap of at least 60,000 years between mtEve and Y-chromosome Adam. In fact by the time Y-chromosome Adam evolved the mtDNA line seems to have already split into an M and N version. This raises the question of what people had mtEve?s line been breeding with to sustain the mtDNA line over those 60,000 years?

The splits in the mtDNA line within Africa seem to simply indicate a slow northward movement from southern Africa beginning about 150,000 years ago. In spite of any propaganda M and N didn?t come out of Africa themselves. Their ancestors came out sometime after the mutation that gave rise to L3 in Africa, perhaps as long ago as 85,000 years. Modern humans had certainly made it into the Middle East by 90,000 years ago. Neanderthals replaced them there about 70,000 years ago but it?s likely the mtDNA remained. The lines M and N were selected for outside Africa, perhaps divided by habitat when they came up against the first obstacle to their expansion: the Zagros and Taurus Mountains. At a guess I?d say N developed in the south-facing hilly regions while M went round the end onto the open Iranian and central Asian plains.

After what seems to have been a period of selection M?s line and her descendants rapidly expand east through central Asia to the far shore and then south along it. Y-chromosome Adam?s descendants may have caught up with them by this time. But for quite a while mtEve?s descendants may have had children with men already there. Back at the western end of the distribution M?s line eventually gets into India from the Northwest, almost certainly with Adam?s Y-chromosome line. After M?s initial expansion around the world a series of mutations give rise to regional varieties. Eventually one of these mtDNA lines (Q), along with a small amount of M?s line, makes it to New Guinea, probably about 30,000 years ago. Just a small proportion of M gains a toehold in Australia, but no Q. Others of M?s descendants remain in Central Asia and eventually move to America (C and D).

A few of N?s line and her descendants eventually move onto the plains as well and follow M. They move through territory already occupied by M and her descendants, into Iran and the Middle East, and a few of N?s descendants even move back to North and East Africa. But in Asia N eventually moves past M?s descendants and arrives in Australia at least by 50,000 years ago. N?s descendants A, B and I eventually reach America.

From this time on it gets complicated. There was a huge expansion of R?s mtDNA line at some time. R evolved from N, possibly in Wallacea, and her descendants are spread from North Africa, across Central and Eastern Eurasia, into America and right down to Australia, New Guinea and Polynesia. R?s descendants mixed with earlier lines including M and N lines and their descendants. But by this time mtDNA lines had been reduced to just those of mtEve. At the western end of the R mtDNA expansion H, T, J and U along with a little N move into Europe.

Now a look at the Y-chromosome line. The first split in the Y-chromosome Adam line seems to be when a group moves into the Central African forest, perhaps a little more than 60,000 years ago. This Y-chromosome line, B, is especially common in modern day Pygmies. The defining moment for the Y-chromosome Adam line outside Africa appears to be when it reaches India. This may be associated with the movement of mtEve?s M line into that continent. All modern non-African Y-chromosomes descend from just two, or possibly three, lines. C probably originated on the Iranian plateau, but it moved into northern India and also to central and eastern Asia. This C Y-chromosome line eventually crossed central Asia to reach Australia, probably with mtEve?s line N.

The expansion of D and E must be more recent than the YAP Y-chromosome mutation that defines them, about 50,000 years ago. E expanded around Africa in force and moved into the Middle East. There is possibility evidence interpreted as a migration out of Africa 40,000 years ago is actually evidence for a migration into Africa.

F seems to have originated in India. Some of his descendants also move north and follow C?s expansion but they don?t move as far. Some of these people (Y-chromosomes I and J) may give rise to the Cro-Magnon of Europe. Others of F?s descendants (K) go in the other direction and follow the coast east, presumably breeding with women they meet on the way. For several reasons these women are unlikely to belong to the mtEve line but M?s mtDNA line may have gone with them. It?s more likely that the mtEve line M had already moved south down the east coast long before. In Southeast Asia the lines definitely meet. The two lines, along with M?s descendant Q, move to New Guinea about 30,000 years ago. Y-chromosome K also moves into already occupied Australia. There seems to have then been an expansion of Y-chromosome K?s descendants west and north back from around New Guinea, probably associated with improved boating technology developed in Wallacea. This expansion is particularly interesting. One of its descendants (Y-chromosome R) reaches Europe, possibly with the descendants of R mtDNA.

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This was fascinating to read. 2 lots into Australia though (M and K).. is this widely accepted? I've never seen it suggested before but it would accomodate some of the controversial stuff like the Mungo skeleton- but your suggestion M seems earlier than that discovery.

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Ellis. It certainly would account for the difference between Mungo and Kow swamp fossils. The belief in two or more migrations into Australia was popular years ago but these days the two types are considered to have evolved in Oz. Simply opposite ends of a cline of variation. Unlikely to have such difference on a relatively small continent. The Aborigine languages are usually divided into two groups. Suggests two migrations. Humans seem to have been in Oz by at least 50,000 years ago and probably longer. I'm presuming the first there basically filled the continent and so N mtDNA and C Y-chromosome were first there in spite of M mtDNA having reached mainland SE Asia before them.

Humans didn't get to Melanesia until about 30,000 years ago, presumably because they didn't have the boating technology to get that far until then. There is also no evidence for people in New Guinea until then but that could be through difficulty of fossil preservation. But they could have died out with changing climate and rise of sea level during the slight warming from 50,000 years ago. Cavalli-Sforza does suggest the the sepik/Ramu of NG may be very ancient though. On the above theory of first in best dressed I'd say Y-chromosome K and mtDNA M came in with the next lowering of sea level starting 30,000 years ago.

People from Melanesia and New Guinea look a lot different from Australian Aborigines. But anthropologists have long believed similar-looking people made up the Hoabinhian culture of SE Asia until about 5000 years ago. People from further north replaced and interbred with them from that time. East Timor appears to be partway through this process. This combination spread into the Pacific, evolved into the Polynesians and arrived in NZ a little less that 1000 years ago.

For anyone from America I see I've made a booboo but I can't be bothered editing it. Of course I mtDNA gets nowhere near America. how did that slip in? Might be some there today with much more recent immigrants.

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Thaks for the explanation-- but now I am a bit confused. If humans were in Oz by 50,000 years ago how did they get there given that there is an objection to Melanesians inhabiting their area before 30,000 years ago because of "boating technology" not being advanced enough. Given that there is a visual resemblance to the (extinct?) Hoabinhian culture of SE Asia would it be reasonable to assume that the original inhabitants of Oz got here via a land bridge? If so, I thought that this theory had been discredited. How else do you suppose they may have reached Australia though? However it would, as you point out, explain the possibility of 2 waves of people.

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Ellis. I've made a real study of Polynesian origins and I reckon this is the early history of the region.

The first people to Oz must have had some boating technology, otherwise they couldn't have got there. Fishing from bark or reeds tied together is a possibility. They almost certainly crossed Wallacea during the ice age (lowered sea level) from 75,000 to 50,000 years ago. Alan Thorne from ANU has claimed the Mungo fossils resemble contemporary fossils from China, Borneo and the Philipines rather than from SE Asia. Presumably the first Australians moved south down the East Asian coast. A rapid movement, similar to the Austronesian movement through the region 50,000 years later, would account for the minimum interaction with people already there.

When sea level rose again populations on small islands probably died out, through inbreeding if nothing else. Meanwhile back in mainland SE Asia the boating technology would have eventually been adopted and improved by the pre-existing population. With the next drop in sea level, at 30,000 years ago, off they went across Wallacea. Even reaching the northern Solomon Islands. Their boating technology was incapable of taking them further. The rest of the Pacific had to wait until the Austronesians had improved boating technology yet again (seems to have been in Taiwan) to feel the benefit of human occupation.

It's often claimed that Oz and NG are connected at times of low sea level but it's as likely that just a series of islands pop up between the two. As for NG, the south coast is fairly low-lying and heavily forested. Historically this has not been prime human real estate. The first lot through the region may not even have come that way. They may have been largely confined to the northern coast. The Sepik/Ramu group of languages is confined to the northern coast.

Yes, the Hoabinhian is extinct but their ancestors presumably still survive. This may explain the genetic difference between northern and southern Chinese.

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Again I can't resist. In case any of you may accept the idea modern humans came out of Africa in a rush and headed straight to australia via India try this:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1180321

And regarding the possibility the out of Africa theory is supported by evidence that actually shows a movement into Africa:

http://www.ncbi.nlm.nih.gov/entrez/query...t_uids=17170302

This is just the abstract. Can't find the entire article on line.

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Recent Archaeological digs here have found that several attempts at populating these islands (Samoa) were made as early as 7,000 years ago, but successful colonizing didn't happen until 2,000 years ago. That Time Line Theory looks valid.

It would also help to explain why so many people are driven to visit Africa. You would not BELIEVE the tourists there. I spent 7 weeks in East Africa in 1997. In fact, it was 10 years ago this month that I went over. One of the most bizarre scenes I have ever experienced took place in a town called Arusha in the Ngorongoro Crater in Northern Tanzania. Busloads (Mercedes Buses, BTW) of frail old Germans pulling up, not even shutting off their diesels, (can't let the Coach get too hot, vershtand?), and these old fogies standing one at a time in front of a line of Maasai to have their photos taken. The photog was another German and he had one of those little battery operated fans. A hot young German Tour Guide in sucked-up tight khaki shorts ushering them along, the Driver whispering, to the girl, "mach schnell, mach schnell", just hilarious.

But the thing is, we DO have some kind of atavistic drive to go to Africa.

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Yes Wolfman. I've even been to Africa. But I went to follow the development of the blues. Therefore I was in the west. But still the most amazing thing about Africa is the people. A most fascinating set of cultures.

There is evidence of humans in NZ dating to about 0 AD but it's most unlikely they left descendants. It actually makes sense that the first people into any region arrive in too small numbers to achieve a breeding population. They go extinct. Butb eventually some people survive long enough to contribute genes to the next lot, hybrid vigour and away we go.

I was certainly under the impression that humans had reached Samoa in numbers by 3000 years ago though. It took another thousand before they could move further east.

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Apologies for returning to this but after considering the evidence again I've changed my mind about my comment:

"After what seems to have been a period of selection M's line and her descendants rapidly expand east through central Asia to the far shore and then south along it".

For what it's worth I now believe M herself developed in East Asia. Certainly didn't come out of Africa although presumably her ancestor did.


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