Just read Spencer Wells’ book Journey of Man, a brief but thorough survey of human population genetics in the vein of Cavalli-Sforza’s The Great Human Diasporas and Bryan Sykes’ Seven Daughters of Eve. While Sykes focused on Europe and mitochondrial DNA lineages (the mother line) Wells puts the spotlight on Y chromosomal lineage (the father line). Wells gives a few reasons why the Y chromosomal lineage can yield more information-there are more points for mutations to build up and human patrilocality tends to skew toward male genetic localization and diversity.
The book has less fluffy filler and more “red meat” than Sykes’ work. Like Sykes, Wells is trying to make money, though he is an independent consultant rather than a businessman, so he has incentive to make this field “exciting.” Basically Wells is doing archeogenetics-tracking movements of populations using genetics. Human beings have an inordinate amount of interest in their origins-so it makes sense that we would care about our recent antecedents at least as much as which branch of the more ancient hominid lines we issue from. Much of the data that Wells draws upon comes straight from the Human Population Genetics Laboratory at Stanford University (follow the links and see detailed publications which offer more than the sketches given in the book). Of course Wells draws from the work of other laboratories to fill in the gaps but the major selling point of the book seems to be his insider point of view, and in contrast to Sykes he doesn’t get tedious about the interpersonal details and let it overwhelm his narrative. The fact that Wells made a film on this subject for PBS probably helped him frame the story in a more compelling fashion.
There are a few obligatory chapters that serve as a genetics primer (though he continues to insert these elucidations throughout the work after the introduction which can be distracting) and descriptions of the scientific methods that have made analysis of Y chromosomal lineages far easier than in the past. To lay persons the methodology will be uninteresting and to those in the know it will be redundant and simplified, so though these sort of chapters are necessary to make a book of this sort seem complete, I doubt many will read them closely.
You hit the payoff near the end of the book, especially chapter eight, titled The Importance of Culture, which is a detailed exposition of the current knowledge in archaeogenetics, slanted a bit toward Wells’ own researches and travels (chapter eight also has a nice map of the movement of markers that transmits the gist). But before I hit this, I have to address a few minor political points. Like his mentor Cavalli-Sforza Wells innoculates himself against any charge that he is studying race. On the back cover there is a blurb from one Dick Lewontin and a paean within to his study back in the 1970s that showed that most human genetic diversity was not between races, in fact less than 10% . Wells also attacks C. S. Coon, the physical anthropologist who published The Origin of Races and elaborated a theory that pre-dated the modern multiregional camp, arguing for five human subspecies that attained sapiency independently . Milford Wolpoff rebuts the naive charges of racism against Coon in Race & Human Evolution and highlights the differences between modern ideas of multiregionalism and their percursors, such as Coon’s theory . Wells several times attempts to paint the multiregionalists as deluded cranks. I personally do think the evidence for Out-of-Africa is compellling, but Wells does not make it clear enough in my opinion to the lay audience that it is still circumstantial, genetics is after all not physics, and multiregionalists are not Steady Staters . An argument can be made that Wells is trying not to muddy the waters in a book that is only 200 pages, but that is no excuse for giving the public a misimpression of the situation on the ground.
There are also a few attempts by Wells to explain human adaptations and delve into evolutionary psychology-he lauds Toobey & Cosmides in one section-but they are sleepers compared to the rest of the book. But there was one section that he seemed to dwell on, and which ties in to his focus on the north-south difference in the Out-of-Africa migrations. On page 117 he talks about the “central Asian” clan forged in the fires of the brutal tundra (so to speak):
The Eurasian interior was a fairly brutal school for our ancestors. Advanced problem-solving skills would have been critical to their survival, which helps us to understand why it was only after the Great Leap Forward in intellectual capacity that humans were ready to colonize most of the world. During their sojourn on the steppes, modern humans developed highly specialized toolkits…The problem-solving intelligence that would have allowed Upper Paleolithich people to live in the harsh northern Eurasian steppes and hunt enormous game illustrates something that could called the ‘will to kill.’
Wells’ own ancestors did come from the interior of Eurasia, as did some of his wife’s (she is mentioned as Hong Kong Chinese). But these were not the ancestors of most Africans or Australians, and few southern or western Asians. I will let readers connect the dots-but Wells talks about Calvin’s idea of the Ice Age being a sort of pump that pushed humans back and forth and served as an impulse for higher intellectual development.
So after Spencer makes a few half-hearted attempts at evolutionary psychology and natural history, he gets to the real meat, the preoccupation with ancestry, and the “clans” of humans (let’s give him a good wink here). I’ll sum up the main points in the book, with my own personal interjections. I suggest GNXPers read chapter 8 in the bookstore, the rest of it most who were well-read in evolutionary sciences already know (and to be sure much of chapter eight is cobbled together from the work of others).
Africa: That’s where we come from. All of us. Those of us from outside Africa come from the northeast corner-in two major streams, one out along the Somali coast and another up through the Levant.
Europe: Wells quotes the 80/20 Paleolithic/Neolithic split as definitive. Basically Wells asserts that Europeans are mostly the descendents of Cro-Magnon people who have their origins in the central Asian cauldron. He has done research relating the remnants of the Sogdian people in Tajikstan (Yangbonis) to the English rather than the Uzbeks of the lowlands. Wells is obviously onto something here, but I did not find the updated figure that others are pushing, that Europeans are 50% descended from Middle Eastern farmers. In either case, there is a NW to SE gradient, while Greeks even in the 80/20 scenario possibly being closer to Levantine peoples than to Swedes. The European “bioculture” as some would say is the byproduct of a cocktail of Levantines and Cro-Magnons, the only question is the portion of each. I don’t know where that leaves the Indo-Europeans, but I suspect that they were neither Cro-Magnons nor the first farmers-I think elite dominance is the way to go in Europe (and Wells seems to settle on this position as well).
East Asia & America: The northern wave that passed through central Asia and the southern wave via India and south east Asia seems to have met up in China. Some of the southern wave mingled early enough to push their genes over the Bering Strait to the Americas when the Siberian hunters populated it. Cavalli-Sforza’s results that clustered northern Chinese with Europeans and southern Chinese with southeast Asians probably result from the higher portion of central Asian ancestry in the north. Rushton has wondered as to this result as the south Chinese have rather high IQs, but in this case, recent cultural practices might have had a stronger selective pressure than ancient adaptations during the Ice Age, as that aspect of phenotype converged in both north and south under the influence of the same culture. Unlike Europe, the agriculturalists in eastern Asia swamped the peoples of southeast Asia that were related to the Australian Aborigines and are to be found among the remnants like the Negritos and Andaman Islanders (even under the 50% Middle Eastern scenario northwest Europeans are mostly Cro-Magnon). Wells does not dwell on this difference, but obviously the descendents of Cro-Magnons were more flexible and more difficult to overpower than the scions of ancient beach-combers.
Australia: This ancient land is the most pure repository of the “southern wave.” Henry Harpending, whose work Wells knows because he mentions it, suggests that the Great Leap Forward did not impact the Aboriginal peoples of Australia much at all. This whole area is filled with political land-mines, so of course Wells would tend to be careful here.
India: There is a strong signature of the “southern wave” in the female line though little in the male line. An early branch of the “northern wave” pushed into India around 30,000 years ago and is like an equivalent to the Cro-Magnon’s of Europe. There were later “agricultural” waves from the Middle East around 10,000 years ago. Finally there is one marker Wells mentions that is prominent in much of India and eastern Iran called M17 that is also prominent in eastern Europe and seems to be from southern Russia. It, like many of the other markers, shows a strong NW-SE grandient, in this case, being found in 35% of men in Delhi but fewer than 10% of men in the Dravidian south. The dots are easy to connect.
Middle East: Not much to say here. Western Iran and eastern Iran are more different than one would think and there is little evidence for the “southern wave” in the Middle East, indicating that they didn’t push farther inland. Seems the Middle East is important more as the starting point for migrations, primarily because its early role as agricultural innovators, sending culture & people north, west, south and east.
I could say more-but read the book. The details will change over the years, but I think Wells has presented a good hint of the outline that will be discerned about the history of human movements.
Update: Here’s a version of the map in question (this is simplifying the picture of course!)….
 See this article by Steve Sailer taking on Lewontin’s assertion. Additionally Wells does not even hint at the fact that Lewontin is a politicized Marxist who played a critical role in personally attacking E. O. Wilson during the sociobiology controversies of the 1970s. In fact, though S. J. Gould continued the good fight on behalf of the “anti-hereditarian” Left until his death, Lewontin faded away from public view, but books like Defenders of the Truth: The Sociobiology Debate, pin-point him as the real svengali behind the scientists who made the scientific controversy into a circus.
 Caucasoid, Mongoloid, Australoid, Congoid and Capoid were the races (at least from what I remember). Congoid and Capoid refer to the “black” and “Khoisan” peoples of Africa, while the others are rather self-explanatory.
 The short of it-Coon spoke out against racism early in his career, but he never developed the hypersensativity to racial questions that other anthopologists did after World War II, so it was easy to paint him as a Neandertal. His scientific theories can be salvaged only through intense modification-but the attacks that Wells and others engage in against him are very personal and accuse him of being an unreconconstructed bigot, I think to cover their own attempts to do what Coon did-reconstruct human racial history. Additionally they use Coon’s quasi-multiregionalist ideas to taint modern multiregionalism as retrograde. Never one to not use tools at their disposal multiregionalists like Wolpoff paint the Out-of-Africa camp as vicious propogandists for the racial supremacy of modern Homo sapiens. Oh, and I have to add that Wells makes a big deal about the fact that Coon thought that Africans were an evolutionary “dead end.” I didn’t really get this from Coon’s work, but perhaps it’s my memory, but in any case, Wells himself contrasts the relatively easy life of beach-combers (southern wave) with the harsh life of northern Eurasians (northern wave). I can’t but help wonder if he’s trying to throw people off.
 To take the anology further, while it is hard to imagine a synthesis between static and expansionary universes, it does not seem impossible that both multiregionalism and Out-of-Africa hold a portion of the truth.