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Do differences in Neanderthal gene content shed light on early migrations?

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In “Breeding with Neanderthals helped humans go global,” ( New Scientist, 16 June 2011), Michael Marshall tells us,

When the first modern humans left Africa they were ill-equipped to cope with unfamiliar diseases. But by interbreeding with the local hominins, it seems they picked up genes that protected them and helped them eventually spread across the planet.

The publication of the Neanderthal genome last year offered proof that Homo sapiens bred with Neanderthals after leaving Africa. There is also evidence that suggests they enjoyed intimate relations with other hominins including the Denisovans, a species identified last year from a Siberian fossil.

The authors say that half of European HLA-A alleles come from other hominins, as do 72 per cent for people in China, and over 90 per cent for those in Papua New Guinea, suggesting that

they were increasingly selected for as H. sapiens moved east. That could be because humans migrating north would have faced fewer diseases than those heading towards the tropics of south-east Asia, says Chris Stringer of the Natural History Museum in London.

Interesting, but makes one wonder why the Neanderthals are still classified as separate species. News value?

There is no inconsistency here. You are seeing inconsistencies where there are none.
Hi Lizzie, Well, from my pov, if there are many ways speciation can take place, and many rates at which it occurs, that is the very definition of inconsistency. Mung
Mung: a gradual process can still be relatively rapid, and when speciation occurs, for example, when a sub population becomes separated from the main population in a very different environment (the other side of a mountain range, for instance) the process may well be rapid. What I mean is that it happens in gradations - there are stages in the speciation process when hybridisation is still possible but rare. Indeed between some very distinct species today (lions and tigers, for instance) hybridisation remains possible. And then there are ring species, in which the species at the extremes cannot interbreed, but all species can interbreed with the next species along. There is no inconsistency here. You are seeing inconsistencies where there are none. Joseph: Yes, if you prevented two human populations from interbreeding over a very long time-span, they might well eventually become two different species. As for same-sex couples - that is irrelevant. We are talking about populations here. In any population there will be infertile individuals, for many reasons. That doesn't make them a subspecies, obviously, because every single organism is directly descended from a fertile parent, and an entire population of infertile organisms wouldn't be a species because it wouldn't breed at all. Elizabeth Liddle
ok, so. I just filed my application today to trademark Neanderthal Jeans. Our slogan, "Every Human has at least one pair of Neanderthal Jeans." Mung
Elizabeth Liddle:
Because speciation is a gradual process.
Except when it isn't. As in, speciation never happens suddenly or rapidly? Sudden Speciation
Polyploidy is a mechanism that has caused many rapid speciation events... ...It has been suggested that many of the existing plant and most animal species have undergone an event of polyploidization in their evolutionary history. - http://en.wikipedia.org/wiki/Speciation
Surely you knew this to be the case, Elizabeth. So why would you make such a statement? Folks, this is what is meant by the claim that evolutionary theory is not a unified and coherent theory at all, but rather a smorgasbord of theories which the evolutionist shifts between as required to make her argument unfalsifiable. Mung
van, Ya see if it wasn't for international travel each country would be well on its way to be a seperate species. And if we kept people apart then it would be a form of artificial speciation. Can't breed if we don't let them. Which brings us to same-sex couples-> they cannot interbreed with their chosen mate, are they a different species? IOW just go with it- we are all transitionals and we can all be our own seperate species. Joseph
and what is your evidence for that? van
Because speciation is a gradual process. It looks as though the process of speciation had begun, with separate non-interbreeding lineages established for quite a while, but that the two lineages later merged (with the greater contribution being from the non-Neanderthal lineage). Elizabeth Liddle
"Interesting, but makes one wonder why the Neanderthals are still classified as separate species." Right. Blacks and Mexicans and whites can all breed together yet science has no problem saying we're all the same species.....so what gives with those from Neander? Why, now that it is positive that they bred with "regular" humans, are they still considered a separate species? The only possible explanation is bias. van

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