(Apologies to) Milford Wolpoff *Updated Again*

*Update Jan. 2016* It has come to my attention that this post is being linked to from a white nationalist forum as supporting the idea that “whites were never in Africa – it’s another white liberal lie.” I know white nationalists are not particularly known for their skills in reading comprehension, but I still want to point out that this isn’t the case at all. How you get that out of “non-Africans have a 4% Neanderthal admixture in their DNA, and Melanesians also have Denisovan admixture” is beyond me. If you’re a white nationalist, you don’t care, but if you are generally interested in what effect the archaic species admixtures have on the populations that have them, can take a look at Milford Wolpoff and Shauna McNally’s comments to this post and Wolpoff’s more recent research. For more on what this means in terms of racial genetics, you listen to Wolpoff’s bloggingheads interview with Razib Khan here. In other news, if you’re a white nationalist, you make me sick. *End Update*

Although it seems that the big news in paleoanthro this week is the unveiling of Austrolopithecus sediba fossils and not Milford Wolpoff at all, interest in paleoanthro naturally begets more interest in paleoanthro, so I figured why not talk about – and apologise to – Milford Wolpoff?

Milford Wolpoff is a professor of anthropology at the University of Michigan, and the most prominent proponent of what is known as the “regional evolution hypothesis“. Regional evolution is one of the ideas for origins of modern humans worldwide. Much as its name suggests, the hypothesis proposes that the evolution of homo sapiens from earlier homo species happened in different regions of the world. This is not to say that the evolution events were separate, but the evolutionary paths in the various regions, the hypothesis says, were partly dictated by the archaic homo that were already present in those regions (for example, the Neanderthals in Europe). It is usually contrasted with the recent african origin theory, which posits that anatomically modern homo developed once, and then went on to replace all other hominins. The specifics usually cited involve a start in Eastern Africa, after which the sapiens replaced all the archaic homo species in Africa, and then migrated out of Africa between 150,000 and 100,000 years ago, stuck around North Africa and the Middle East for a while, and then, about 50,000 years ago expanded into Asia and Europe, completely eliminating and replacing the homo species that previously occupied those regions.

Morphologically and archaeologically, the two theories were somewhat competitive, although most evidence did point to a recent African origin. But it was genetics that really sealed the deal for Out-of-Africa in the 80’s. In a seminal paper in 1987, Allan Wilson, Rebecca Cann and Mark Stoneking traced out a common ancestor for all living humans using mitochondrial DNA (mtDNA). Mitochondrial DNA is DNA that is unrelated to the DNA of the human host, and so is not strongly subject to environmental selection, and varies slowly and at predictable rates. It is also passed on matrilinearly, so by comparing mtDNA of two subjects, you can discern a time when the common matrilineal ancestor of the two people lived. Wilson Cann and Stoneking showed a “mitochondrial Eve” living about 160,000 years ago, and the first split being between the Khoisan and the non-Khoisan peoples. This was considered a slam-dunk for the recent out of Africa hypothesis.

Yet, though greatly marginalised, Wolpoff persevered in championing regional evolution. But the only other people in the field who agreed seemed to be either his students or his ex-students, giving the hypothesis the whiff of almost a cult, and an unconvincing one at that (to me, at least).  In the piece of writing I put the most effort into so far in my life, I wrote that this idea should be dismissed “out of hand” and specifically didn’t provide a citation just to show off how uncontroversial I thought this claim was. I would even insult the idea for no reason when talking about something else. for instance naming “Milford Wolpoff vs. anthropologists who aren’t crackpots” as a rivalry alongside “Habs vs. Leafs” and “Beatles vs. Stones”.

A melanesian kid (look ma, no hair dye!)

The professor of my first biological anthropology class (Brian Chisholm) held the opinion that neither theory was entirely correct, and the truth lay somewhere between the two. This seemed to me mealy-mouthed and ridiculous. How could there be a middle ground between regional evolution and total replacement? What, did the moderns invading Europe have “just a little bit” of sex with the Neanderthals, I scoffed? Well, turns out, current best science seems to suggest that that’s exactly what happened. This knowledge is thanks to Svante Pääbo’s group at the Max Planck Institute for Evolutionary Anthropology in Leipzig who sequenced the genome of the Neanderthal and the Denisovan hominin. It’s pretty mind-blowing that this could be done, actually. But the upshot is that around 4% of non-Africans’ genomes are shared with Neanderthals, which suggests that little bit of sex I was talking about. And with Densiovans, it’s even stranger: 4 to 8% of their genes are shared with Melanesians (who by the way live nowhere near Siberia, and are sometimes blond despite being dark-skinned), but not with other humans. And now, Razib Khan writes of new research where modelling of African DNA from modern populations suggests an admixture from archaic homo as well. It turns out that, perhaps not in details, but Milford Wolpoff was, in a lot of ways, right.

Wolpoff once claimed – and I am possibly misquoting here because I can’t find a reliable source on the internet, but the quote is good enough that I can’t let it be unsaid in clearly the only thing on Milford Wolpoff I’ll ever write – “Data do not speak. I have sat in rooms with data for hours and didn’t hear a thing.” And yet these data seem to speak pretty loudly in favour of at least a mild form of regionalism to go along with the out-of-Africa theory. So, professor Wolpoff, my apologies, and for the rest of us, a reminder that things that we choose to consider settled questions in science are sometimes anything but.

*Update*

Milford Wolpoff, and Shauna McNally, a former student, have clarifying replies in the comments. Be sure to read them!

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7 Responses to (Apologies to) Milford Wolpoff *Updated Again*

  1. Milford Wolpoff says:

    Thanks! You have it mostly right, and I appreciate your attention. I’d make 2 points. The first is that it was never a question of how much gene flow took place, but rather whether the genes were important, were they under selection so that they had important effects. Some of the Neandertal genes that have persisted are definitely advantageous, for most of them we don’t know yet (nor do we have anything like a complete listing). That brings me to the second point, the percentage of Neandertal genes in human populations is a far higher than the percentage of the human population that was Neandertal. See this either indicates a lot of interbreeding, or (what I think) selection. For 30 years there have been two theories; one that modern humans appeared recently as a new species from Africa, replacing other populations, and the other, that modern humans are the people alive today (not a taxonomic entity) and that they evolved b y normal evolutionary mechanisms from earlier populations – especially selection with gene flow. That’s MRE.

  2. Shauna McNally says:

    Yep. As a former student of Dr. Wolpoff (one of the members of the “cult” you are talking about), that was definitely him writing you back. What other paleoanthropologist would have been so polite?? Contrary to almost everything I´ve ever read criticizing the theory of multi-regional evolution, the field takes all relevant evidence into account (even genetics!), and never states that modern human populations developed in isolation (i.e. moderns went to asia, mixed with homo erectus, and those people made modern asians…this is not what multi-regional evolution says), but that there was constant gene flow going in all directions from all locations, and modern humans are influenced by the ancient populations that came before them. If you have studied these fossils and how regional populations develop over time, this becomes readily apparent. Dr. Wolpoff has said all along that although the mitochondrial Eve theory threw a wrench in what people believed, slowly but surely, the very new (and sometimes incorrect) field of genetics would begin to support what the fossils have said all along. And this has been happening, slowly but surely, since the years I studied with him, and I feel vindicated every time I see more evidence like this in his favor!!!
    One thing that I am not sure is expressed clearly in the article or Dr. Wolpoff´s response is the ability of non-functional regional anatomy to show these links. For example, neandertals have a suprainiac fossa, an indentation just above the occipital bone on the back of the head. There is no known selective advantage to this trait. Approximately 2% of modern european decedents also have a suprainiac fossa. This trait is seen in no other populations besides modern european decedents. I just so happen to have a suprainiac fossa on the back of my head, the only one I have ever seen (or rather touched as it is on the back of my head) besides the backs of the neandtertal skull casts we studied. Where exactly do you think that came from??? There´s not a whole lot of explanation for that, and the same thing is present in variations of regional anatomy all over the world, study Milford´s work and you will learn about these regional variations of modern populations that are eerily similar to the anatomic traits of the ancient humans in those regions. Coincidence? After seeing the same pattern on many continents, it´s hard to claim global coincidence.
    What I like to hear in this genetic news is that modern humans and ancients interacted on a pretty small scale in the overall evolution of things, but it was enough to influence modern populations, and this is what multi-regional evolution has said all along. The anatomy of those fossils does not lie!!! And thanks for giving Milford some credit, he is one of the most brilliant paleoanthropologists of our time.

    • Lee says:

      I could not agree more. I’m not one of Dr. Wolpoff’s student, merely a hobbyist with a passion. Researching my own personal views, which were not in alignment with strict Out of Africa recent replacement theory, led me to Dr. W’s work. I deeply admire and appreciate his conviction and tenacity in the face of hostile, mudslinging opponents who should ready their plates for a big helping of crow.

  3. zolltan says:

    Milfrod, Shauna, thank you for your replies. Although I think I was being honest in my post, I should have been slightly more tactful if I knew you’d be reading it! I think I pointed out that MRE does not imply a lack of contact between populations, but it’s always good to reiterate this point.

    I wonder why Out of Africa and Regional Evolution were seen to be opposing camps (at least that was my impression). Was it just an impression? Looking back, it seems like a large-scale population migration out of Africa and MRE are not in any way contradictory, just a question of emphasis. Or am I putting words into the mouths of MRE supporters about a belief in large-scale out of Africa migration – to me the evidence definitely supports this as well.

    One thing I wanted to clarify: how do we know there were less Neanderthals in the human population than their genetic imprint indicates? From Dr. Wolpoff’s reply, I have the impression that he thinks that the portion of Neanderthal genes in modern non-Africans includes a component under selection, which I guess hinges on the above question. Is that correct? My other question is how to determine these potential selected-upon Neanderthal traits. Presumably, strongly selected traits should be harder to spot than seemingly non-selected traits like suprainiac fossae, since they would have spread widely with sufficient gene flow? Please excuse my continual question-asking, I’ve really fallen off following what’s current in anthropology, being that I now work in physics, but I’m super interested about this!

  4. Pingback: Most Recent Common Ancestor | Rated Zed

  5. Pingback: Svante Pääbo | Rated Zed

  6. I appreciate your comments about Milford Wolpoff. I always thought it was odd that people were so convinced that Neanderthals and modern humans had not interbred based on the mitochondrial data.

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