Sunday, December 13, 2009

254. The Baseline Scenarios -- 30: The Migrants -- Morphology

Before getting into the complexities of the cultural history, let's see how far we can get when we get physical. Admittedly, the cultural aspect interests me much more, but now that we've reached this point, I can't resist speculating about the physical stuff as well.

Two very intriguing questions immediately come to mind: 1. is there any evidence that HMP were short, like today's Pygmies -- and also certain Bushmen groups; or is it more likely they were of "normal" size, or even taller? 2. is there any evidence that could help us decide whether HMP were morphologically closer to Pygmies or to Bushmen? I think there is evidence that could help us on both counts, though some of it is inconclusive for sure.

To deal with the "easy" question first, it seems evident that HMP must have been more Pygmy-like, 1. because there are a great many "negrito" peoples in South Asia, Southeast Asia, Indonesia, and Melanesia, who have a decidedly "pygmoid" physiognomy; 2. there are also a great many taller peoples who strongly resemble Bantu Africans, who are closely related genetically to African Pygmies and look far more like Pygmies than Bushmen; 3. no other people in the world look like Bushmen,* while a great many resemble African Pygmies; 4. the genetic evidence seems consistent with Pygmies, or at least proto-Pygmies as ancestral to everyone else, while mtDNA L0, characteristic of most Bushmen, seems relatively isolated, with no out of Africa branches at all. I'm aware, of course, that there are some striking similarities between modern East Asians and Bushmen, including the epicanthic fold, flattened facial features, etc., but I don't see any evidence of a direct or intermediate link between the two populations, so this might well be a coincidence -- (or perhaps the late "flowering" of some recessive genes).

As for shortness, this is a more complex issue, because we still don't know whether the shortness of all or even most Pygmy groups is inherited from a common ancestor or represents a series of independent adaptations. What we do know is that every single "negrito" group in the world is located along the hypothetical southern coastal route supposedly taken by HMP after leaving Africa for Asia, and it would seem difficult to explain the presence of so many of these groups -- many of which are hunter-gatherers with a culture very similar to HBC -- along this particular path unless they were direct descendants of HMP. It's also true, however, that many, though not all such groups were orginally found living in tropical forest environments, which means that all Pygmy and Pygmoid shortness could be an adaptation to that particular environment (though this doesn't explain Bushmen shortness). It's also true that the great majority of groups now living along this path, and represented by M and N clades, are not negritos. So if HMP were Pygmies, or Pygmoid, then why aren't all their descendants short? If we insist on a single Out of Africa migration, then, at some point, at least one of the descendant groups must have adapted, one way or the other. But this difference could also be the sign that there was more than one Out of Africa migration, and thus more than one HMP, one short, one of "normal" size. Do we need to think in terms of HMP1 and HMP2? and HMC1 and HMC2 as well? As we turn to the cultural evidence, we might find some clues to help us deal with this very fundamental question.

(to be continued . . . )
*[Added 12-14: I should have written "no other people in the world, outside of Africa, look like Bushmen." There are many people in southern Africa who do in fact look a lot like Bushmen, which is to be expected if we accept the commonly held theory that Bushmen and their close relatives, the Khoi-khoi (so-called Hottentots), dominated all or most of southern Africa prior to the Bantu expansion.]


German Dziebel said...

"I'm aware, of course, that there are some striking similarities between modern East Asians and Bushmen, including the epicanthic fold, flattened facial features, etc., but I don't see any evidence of a direct or intermediate link between the two populations, so this might well be a coincidence -- (or perhaps the late "flowering" of some recessive genes)."

Such "Asian" features as transverse facial flatness and shovel-shaped incisors are found at moderate-to-high frequencies in Late Pleistocene skulls from North Africa. Of course, we won't see the epicanthic fold on them but overall these skulls could meet your requirement for "direct or intermediate links." There was some back and forth going on in the discussions between Multiregionalists and out of Africanists in the 1990s regarding these skulls. So this information should be easy to find.

Maju said...

There are other populations "along the coastal route" that are not short: Australian Aborigines or Papuans for example, or even Indians (who used to be much taller, at least in some places in the UP) and all those "giant" peoples of Ethiopia and South Sudan, the latter specially looking very much close to the ancestral HBP, even maybe more than Pygmies.

There is some fossil evidence of archaic large humans (I have already mentioned the large skull of H. sapiens idaltu and the large size of a likely direct antecesor, if not fully AMH, of South Africa). I have also mentioned elsewhere that Pygmies seem to have evolved their short size as adaptation to jungle conditions, particularly the lack of enough iodine in their diets. I have the strong feeling that you are not totally right on the issue of size - and anyhow it's a less important issue, as size is quite plastic in humans.

I also don't fully agree on emphasizing Pygmies or proto-Pygmies as ancestors of all Humankind but Bushmen. I rather think that Pygmies are an offshoot of that node, probably centered at a more prairy-type of ecosystem, and that peoples of East Africa (from Sudan to the Sandawe) are in fact closer to that node (or at least as much as Pygmies).

There is a lot of people that would bet for a human origin at Ethiopia (or somewhere nearby), with the Bushmen and Pygmy branch being perceived more as derivates than sources. This is very clear for the Pygmy branch, I think, though more ambiguous for the Bushmen branch possibly.

As for looks, I can't say for sure. Probably what are common African traits today were also to some extent among the HBP: things like wooly hair, dolicocephaly, short/flat noses, thick lips, dark pigmentation... For the rest it is very difficult to judge, moreso as even fossil humans show large variability.

Omo I has been proposed as the earliest fossil H. sapiens. He shows a broad nasal hole similar to that of Black Africans, very moderate prognathism for an archaic specimen, dolicocephaly and a prominent but thin browridge. I don't know its size but I presume it was rather large, considering what seems to be the case with Idaltu.

Omo I reminds a lot of the early Palestinian fossil humans (Skuhl-Qafez), while the more recent H. sapiens idaltu looks to me similar to Liujiang, which I just read clusters reasonably well with more recent Hoabinhian remains (allegedly "Australoid").

But anyhow, for me trying to reconstruct the look of early H. sapiens is kind of impossible beyond some notions.