»  National Review Online

June 20, 2006

  The Ultimate in Genealogy

Before the Dawn
by Nicholas Wade

——————————

"The proper study of mankind is man." The application of scientific method to that study has, however, proved to be much more difficult than an English gent of the 1730s could reasonably have anticipated. Our common sensibilities rule out all but a very limited range of planned experiments on our fellow humans. Observation and classification, the first phases of any scientific program, are hampered by the great number and variety of people on the earth, and by the complexity of the human organism. They are then further clouded by the difficulty of looking objectively at the behavior of other human beings and groups: see Judith Rich Harris's devastating survey of the academic literature on child development, where she shows that ninety percent of it is scientifically worthless. Measurement, the next essential step in a scientific program, crashes up against widespread modern fears and prejudices, as the history of physical anthropology (not to mention psychometry!) illustrates.

It is therefore not surprising that in the history of the human sciences, false trails and dead ends abound. Two major world-historical intellectuals, Marx and Freud, as well as numerous minor ones, convinced themselves and millions of others that they had developed workable, rigorously scientific theories of human history or psychology, when in fact they had done nothing of the sort, only dressed up some pre-scientific concepts like sympathetic magic in ingenious and seductive vocabularies — the human-science equivalent of alchemy.

A milestone in the real, genuinely scientific, understanding of human nature, perhaps the first milestone of any significance (counting Darwin as belonging to biology at large, not just the human sciences), came in 2003 with the completion of the project to map the human genome — to determine where in our chromosomes each of our 30,000 or so genes is located. Among the follow-up tasks, now being pursued by researchers world-wide, are to figure out what function each gene performs, what varieties ("alleles") it exhibits, what differences in outcome ("phenotype") each variety implies for the host organism, what the frequencies of those varieties are, how the frequencies are distributed in different populations, and — most difficult but most fascinating of all — how groups of genes work together to produce gross features of our human persons and societies, features like intelligence, physical grace, sexual inclination, sociability, religious passion, or aggressiveness.

Early results have been coming in over the past few years. For the educated, interested layman, there has been no more reliable and readable recorder of them than Nicholas Wade, science reporter for The New York Times since 1982.

It is tempting to add the adjective "fearless" there, since many of these results are subversive of the egalitarian, "blank slate," Standard Social Science Model of human nature cherished by the modern Western intelligentsia. A great superstructure of policies has been erected on the SSSM, in policy areas from education to immigration, from welfare to diplomacy. Countless academic, bureaucratic, journalistic, and political careers are invested in it, together with correspondingly stupendous amounts of money. To contradict the SSSM — to assert, for example, that natural selection did not suddenly stop dead when homo sapiens sapiens branched off from the primate family tree, but has been working away even down through recorded history — is to risk being denounced by all the Great Panjandrums of our culture. And yet, as Nicholas Wade has been calmly reporting from his office at the Times — from the very belly of the SSSM beast! — these early results often do contradict the SSSM. In fact, as more and more of these results pile up behind the SSSM dam, they look set fair to burst it altogether quite soon. What will be swept away by that flood, and what the subsequent intellectual landscape will look like, are matters on which we can only speculate.

Wade's new book Before the Dawn brings together a selection of these early results to tell the story of modern man, homo sapiens sapiens. We have known a good deal about this topic for decades, from investigations in archeology, anthropology, and comparative linguistics. However, our new, detailed knowledge of the human genome has clarified our understanding dramatically. A good analogy would be the results sent back by the first interplanetary probes, resolving what for centuries had been mere points of light or fuzzy blobs in our telescopes into actual landscapes of craters, volcanoes, and dunes, while at the same time demolishing wishful-thinking fantasies like Percival Lowell's Martian canals. Genetics has clarified our understanding of human prehistory by a similar order of magnitude. It may even shed new light on recorded history. As for wishful thinking — well, there is far more of that in the human sciences than ever there was in astronomy, so that a prominent feature of the next few years will be the sound of bubbles bursting.

—————————

Before there were modern humans there were hominids, those not-quite-humans who formed one arm of the great chimp-human split of five million or so years ago. The chimps went off on one path through evolutionary space, the hominids on another. By 50,000 years ago there were at least three species of hominid: the Neanderthals in Europe, homo erectus in Asia, and modern humans in Africa. (The recently discovered "hobbit" hominids of Flores Island in Indonesia were probably a downsized subspecies of homo erectus.)

Then a tremendous event occurred. A small band of modern humans — it may have been as few as 150 people — crossed from Africa into Arabia via the Bab al-Mandab ("Gate of Grief") at the southern end of the Red Sea. Their descendants proceeded to populate all of Eurasia, Australasia, Oceania, and the Americas. Moses and Mao Tse-tung, Socrates and Sitting Bull, Gandhi and Geronimo, Queen Anne of England and Queen Liliuokalani of Hawaii, are all descended from that same tiny band. Those modern humans who were left behind in Africa of course had 50,000 years of history ahead of them, too, and Wade covers it fully; but it is no slight on anyone to say that for sheer drama and wonder, the epic of that little group of emigrants and their descendants, told in this book, takes some beating.

They had, for example, to deal with the other hominid species already in possession of Eurasia: the Neanderthals and homo erectus. Deal with them they did, so thoroughly that both species were soon extinct — a conquest of two hominid species by a third. "Soon" is a relative term there, for the conquest took 15 or 20 thousand years. As Wade says of the encounter between modern man and the Neanderthals:

There is no way to know for certain the nature of the interaction between the two human species. It is unlikely to have been pleasant. Hunter-gatherer societies cannot support standing armies, so it is probably wrong to think of the modern human entry into Europe as a military campaign. It was more a slow infiltration. … The modern humans probably moved as they always did, expanding into new territory as communities split, not exploring for the sake of adventure. Each new community would have skirmished with the local Neanderthals … Year by year the moderns' territory expanded and the Neanderthals' shrank. From the extraordinary length of the process — a border war that took 15,000 years to move across Europe — it is evident that they did not yield easily. But by 30,000 years ago the Neanderthals had disappeared from their final refuges in the Iberian peninsula.

We actually have some fragments of DNA from Neanderthal remains. We don't have enough decisively to settle the vexed question of whether moderns and Neanderthals interbred, but such mixing now seems unlikely, except perhaps on a small and occasional scale.

Halfway through the 50,000-year span of modern human history outside Africa, when the moderns were in complete possession of Eurasia (though not yet the Americas), a terrible climatic calamity descended on them: the Last Glacial Maximum. All of north Europe and Scandinavia disappeared under the ice, along with great tracts of northern Asia. This event — which was, of course, entirely natural — far exceeded anything Al Gore could imagine. Pleasant temperate savannah became gale-swept arctic tundra. Wade:

Nothing is known about the collision of peoples that may have been set in train as the people of the north migrated down into the southerners' territory.

When the glaciers finally retreated again 19,000 years ago, the stage was set for the last great developments in human prehistory: permanent settlements, the rise of agriculture, and the occupation of the Americas.

—————————

Drawing on the genetic evidence, Wade fills out this narrative with all kinds of fascinating sidebar facts. We get a full account of the probable origin of clothing, with supporting evidence from genetic studies of lice. The very warlike qualities of our remote ancestors are exposed — readers fond of the idyllic, communal-harmony myth of prehistoric society will have their illusions shattered. The world of a thousand generations ago was no Garden of Eden. Wade also examines the curious fact that the first permanent human settlements occurred at about the same time as the domestication of dogs by man — or, it may almost have been, the domestication of man by dogs. The use of dogs as sentries may have been vital to the survival of those first settlements. (Wolves, from whom dogs are descended, almost never bark. The dog's bark must have been greatly prized, and carefully selected for.)

Language is a key characteristic of modern humans, and probably a unique one, Neanderthals and homo erectus having had it, if at all, only in a rudimentary way. "Fully articulate, modern language must have evolved before modern humans left Africa," Wade explains. One consequence of that is that not only are all non-Africans descended from that pioneer group of 150 or so, but all non-African languages are descended from that group's, presumably single, language. The subsequent development of the world's languages is a major sub-plot in Wade's narrative, with the major controversies about the origins of modern language families fully aired and checked against genetic and archeological evidence for the movements of peoples.

Stricter adherents of the SSSM will be scandalized by the inclusion of a chapter titled "Race," which according to them is a thing that does not exist, except in the diseased imaginations of "racists." Fiddlesticks, says Wade: of course race exists. He proceeds to give a calm, factual account of what we know, again carefully rooting it all in the genetic evidence. Along the way he skillfully disposes of such race-denying SSSM darlings as Richard Lewontin (who argues that because variation between individuals swamps variation between groups, the groups are meaningless) and Jared Diamond (who says it's all just geography … except in New Guinea, where natural selection has made people smarter than us).

Wade is very up to date here, even giving an account of the startling findings by Bruce Lahn that I myself reported on in National Review a few months ago. On the really touchy topics in this zone he is carefully agnostic, which is excusable in a book of this sort. "The fact that different races or ethnic groups tend to excel at different sports," he says mildly, after an account of Jon Entine's book on this subject, "is not proof in itself of any genetic component but just a starting point that hints at possible genes to look for." There is a bit of protective camouflage there — why would a researcher go looking for such genes if there were not a good expectation of finding them? — but again, I think Wade's diffident approach is correct for a book like this, aimed at a broad popular audience raised and educated in the no-such-thing-as-race fallacies.

In a final chapter Wade places the whole story in the context of evolution. He is brusque with pre-scientific explanations of human origins: "Humans are just one of the myriad branches of the tree of life, sharing the same fundamental genetic mechanisms as all other living species, and shaped by the same evolutionary forces. This is the truth, as far as our reason permits us to discover it. All differing accounts of human origin, though a matter of religious dogma for most of recorded history and widely believed to the present day, are myth." He closes with some speculations about how human beings will evolve in the future. "Two choices lie ahead. One is between directed human evolution and the natural kind, the other is whether to allow or promote speciation."

Before the Dawn is beautifully done, a grand genealogy of modern humanity, rooted in fact but spiced with an appropriate measure of speculation and hypothesis. Even for a reader to whom the material is already familiar — one who, for example, has been following Nicholas Wade's reports in The New York Times — it is well worth the trouble of reading this book for its narrative value, for the elegant way Wade has put it all together as a single compelling story. This is a brilliant book, by one of our best science journalists.