Science Refutes Orthodoxy — Again

Gregory Cochran and Henry Harpending, The 10,000 Year Explosion: How Civilization Accelerated Human Evolution, Basic Books, 2009, 288 pp.

The 10,000 Year Explosion is such a subversive book it is surprising it was brought out by a mainstream New York publisher. The authors, both of whom teach anthropology at the University of Utah, steer clear of politics, but the scientific findings they describe have such obvious policy implications that they will reduce liberals to spluttering incoherence — if liberals can bring themselves to read the book.

This volume shatters one of the obligatory doctrines by which the Left lives: that Homo sapiens hardly evolved at all after modern man ventured out of Africa, and that although groups differ in appearance their brains are identical. This is clearly nonsense, but the great strength of this book is to have marshaled so many contemporary genetic discoveries that prove it is nonsense. Far from slowing down, evolution has been speeding up, and the authors argue that for the last several thousand years it has been roaring along 100 times faster than during the Stone Age, making different populations increasingly unlike each other. “The biological equality of human races,” the authors write, is “about as likely as a fistful of silver dollars all landing on edge when dropped.”

Rapid evolution

If one accepts the theory that modern humans first evolved in Africa and began colonizing the rest of the world 50,000 to 60,000 years ago, it is obvious that there has been enormous evolutionary change since that time. Zulus and Danes presumably had a common ancestor about the time humans left Africa, but are now so different from each other that standard taxonomies might well classify them as separate species.

Nature is full of dramatic change. When fish are trapped in caves they lose their eyesight in just a few thousand years. Rapid evolution also occurred when the sea rose at the end of the last Ice Age, 11,500 years ago, and herds of elephants were cut off from the mainland on what became islands. Size is not an advantage on an island, and the fossil record shows that the elephants shrank in height from 12 feet to three feet in just 5,000 years. Elephants have about the same 20-year generation span as humans.

Professors Cochran and Harpending point out that even more rapid evolution is taken for granted by ranchers and farmers, who are constantly raising stock that did not exist 100 or even 15 years ago. They note that every breed of dog has evolved from wolves, which were domesticated 15,000 years ago, and that most of the breeds we recognize today are only about 200 years old. A Russian scientist managed to breed tame foxes in just 40 years — ten generations — by selecting only for tameness and friendliness. The pet foxes lost their musky, fox smell, wagged their tails when they were happy (which wild foxes do not), and liked to lick people’s hands.

People consciously direct the evolution of plants and animals, but the authors point out that the process is no different from the rigors of natural selection — just quicker. Much as the race deniers hate to admit it, humans in different environments evolved in sharply different directions. As the authors conclude, “We expect that differences between human ethnic groups are qualitatively similar to those between dog breeds.”

What, however, caused human evolution suddenly to speed up ten to twelve thousand years ago? For Professors Cochran and Harpending, the short answer is “agriculture.” It did so in two ways: by sharply increasing the number of people and by radically changing the environment in which they lived.

More humans meant more children, and therefore more mutations. Most babies are born with about 100 mutations, all but one or two of which are in DNA that does not seem to do anything and therefore have no effect. Those that make a difference are usually harmful or neutral but it is the occasional helpful mutation that drives evolution. Sixty thousand years ago, before the expansion out of Africa, there were perhaps only about 250,000 humans. By the Bronze Age, 3,000 years ago, there were 60 million, so a mutation that would have taken 100,000 years to occur could appear in just 400 years. Evolution was painfully slow among Paleolithic proto-humans because beneficial mutations show up so rarely in tiny populations.

Large populations are therefore a reservoir of new mutations and their size hardly slows down the propagation of good genes. According to the authors, a genetic leg up is like the flu, and can sweep through a population of 100 million in only twice the time it takes to go through a population of just 10,000.

The power of agriculture

Agriculture also brought perhaps the most dramatic change in the biological and social environment our species has ever experienced. Farming meant that for the first time in their existence Homo sapiens stayed in one place, and could therefore own more things than they could carry with them. They could become wealthier than their neighbors, and had to guard possessions against theft. Farmers could produce more food than their families needed, and this gave rise to commerce, division of labor, artisans, and non-productive elites. This social environment was completely new.

Of particular significance from an evolutionary point of view were the change of diet, domestication of animals, and population densities. The first agricultural diets had little variety and were not nearly as nutritious as the meat humans had been eating for millennia. With little protein in their diets, farmers were as much as five inches shorter than hunters, and any mutations that helped farmers get more out of a cereal diet got around quickly. At the same time, the widespread use of fire to prepare and soften food meant people could evolve smaller teeth than those necessary during the Paleolithic period.

Domestication and herding meant living with animals, and people began to catch their diseases. At the same time, villages produced heaps of rubbish that attracted rats and other disease carriers. New kinds of pestilence ran through populations that were far denser than before, so there was a high demand for genes that gave resistance to disease. Farmers invariably discovered fermentation, so selective pressure also began to weed out excessive susceptibility to alcohol.

In dense communities, in which wealth could be accumulated and traded, complex speech is more important than among hunters. Ownership of land and livestock required new rules and ways to enforce them. People had more to think about, more possessions to look after, and thieves and con men to deal with. All this pushed evolution in new directions.

The nature of agriculture changed human nature. Farming requires more planning and self-restraint than hunting; at the very least, farmers must save seed corn for the next year no matter how hungry they get during the winter. Meat, on the other hand, goes bad in a few days, so hunters gorged themselves rather than save. Farming favored deferred gratification.

Likewise, if farmers worked hard they could make permanent improvements to their land and build safe, comfortable houses. There was no incentive for hunters to build things or accumulate anything they could not move. Once their bellies were full they goofed off until the next hunt. Farming favored mutations that produced steady toilers.

People who lived in densely packed, permanent settlements also had to control anger and violence. If hunters had nasty neighbors they could just move away. Farmers could not abandon their farms, so they had to learn to live with people they did not like. Once governments arose, people had to submit to rulers, and the impulse to reach for a weapon was no longer so adaptive. As the authors explain, “Eventually there must have been many people with personality types that hadn’t existed at all among our forager ancestors.”

There is direct, genetic evidence that agriculture caused rapid genetic change. Sophisticated techniques can indicate how recently distinctive genetic patterns evolved in different populations, and more new genes were sweeping through European and Asian populations about 5,500 years ago than at any time before or since. The huge changes brought on by agriculture were probably the cause.

Sooner or later?

Professors Cochran and Harpending point out that some groups took up farming long before others, and that this explains a lot. Australian aborigines never farmed, and the American Indians of Illinois and Ohio started farming only 1,000 years ago. Both groups never drank alcohol before the white man showed up, and are highly susceptible to alcoholism. Fetal alcohol syndrome is about 30 times more common in these groups than in whites.

Aborigines and American Indians suffer in other ways from only recently having adopted a farming diet. Type 2 diabetes is related to a sensitivity to carbohydrates and a metabolic tendency to obesity. It is four times more prevalent among Aborigines and 2.5 times more prevalent among Navajos than among whites.

Sub-Saharan Africa was also late to take up agriculture — 7,500 years after it arose in the Middle East — and this helps explain why intelligence differences alone do not explain differences in black and white behavior. When the two groups are matched for IQ, blacks are still more likely to be criminal, shiftless, or have illegitimate children. This is probably due in part to the persistence of the smash-and-grab mentality that suits hunters but is gradually bred out of farmers.

Professors Cochran and Harpending note that this probably explains why it is so hard to teach African Bushmen — who never made the switch to farming — to be herders rather than hunters: they eat all their goats. The Chinese, on the other hand, who have been farming a long time, appear to have had virtually all the genes associated with attention deficit disorder and hyperactivity bred out of them.

The authors of The 10,000 Year Explosion understand that population differences of this kind mean that some peoples create civilizations and others do not. Noting that some nations have leapt into the industrial age while others are stuck in poverty, they conclude:

“If the root causes of these differences are biological changes affecting cognitive and personality traits, changes that are the product of natural selection acting over millennia, conventional solutions to the problem of slow modernization among peoples with shallow experience of farming are highly problematic.” The authors propose no “unconventional” solutions.

Some aspects of modernity simply cannot appear without the intelligence — and the genes — necessary to support them. The authors argue that “the scientific ‘revolution’ may well have resulted from modest changes in gene frequencies affecting key psychological traits.” They explain that science probably arose only after a society had a certain minimum number of people who had the temperament to be interested in puzzles and were smart enough to solve them. There also had to be a level of communication within society that allowed ideas to circulate so that smart people could benefit from the discoveries of others. Not all societies, in other words, have the genetic basis for science.

The brain has evolved differently among different groups just as have skin color, body type, and facial features. The authors write that there are recent variants of genes that affect synapse formation, axon growth, formation of the layers of the cerebral cortex, and brain growth. “Again, most of these new variants are regional,” they add. “Human evolution is madly galloping off in all directions.”

Sometimes, even what appear to be racial similarities are actually differences that merely resemble each other. The authors point out, for example, that although both Asians and Caucasians have much lighter skins than ancestral Africans, the genetic mechanisms that shut down melanin production are different in the two races. In both Asia and Europe it was useful to let in more sunlight for vitamin D synthesis, but evolution found different ways to do it.

Milk drinkers

The same is true for lactose tolerance, a surprisingly interesting subject to which Professors Cochran and Harpending devote many pages. They point out that before the domestication of cattle, there was no need for humans to be able to digest milk after they were weaned, and all populations were lactose intolerant until a mutation that occurred about 8,000 years ago among European herding people. Dairying produces about five times as many calories per acre as raising cattle for slaughter, and milk is very nutritious, so it was a considerable advantage for adults to be able to drink it. The mutation therefore swept through Europe.

Thousands of years later, people living in what is now Sudan and Ethiopia developed a tolerance for milk, but their mutation was different from the one that appeared in the north. The authors point out that the ability to drink milk is so advantageous that it would have spread through Africa if even just a handful of northerners had ventured into the area during the Bronze Age. The absence of the northern gene suggests how little contact there was with people south of the Sahara.

Professors Cochran and Harpending speculate that lactose tolerance may even account for the spread of the Indo-Europeans. Around 3,000 BC, nomads who were to have a far-reaching impact began to move out of an original Indo-European homeland that may have been in Anatolia or southern Russia. They eventually spread their language and culture not only throughout Europe but to Central Asia, the Iranian plateau, and the Indian subcontinent. Some three billion people now speak the more than 400 languages and dialects that comprise the Indo-European language group, making it the largest in the world. How did the Indo-Europeans cover so much ground?

The authors think it may have been because they were among the first to be lactose tolerant, and this changed their society in several important ways. First, because it is much more nutritionally efficient to milk cattle as well as eat them, the first milk drinkers could produce denser populations than farmers or other herders. Also, cattle are both valuable and portable — they transport themselves — so herders inevitably become rustlers, which leads to a warrior tradition. Farmers, who had to defend fixed targets, were no match for mobile cattlemen who could attack wherever and whenever they liked. Finally, milk-drinkers had a better diet; there is evidence that Indo-Europeans were up to four inches taller than the people they overran.

The Indo-Europeans appear to have gone on a conquering spree that lasted several thousand years. They are likely to have been a dominant elite that forced their culture on subject peoples but then moved on before they were absorbed. The strong, established states of the Middle East managed to fend them off, but Indo-Europeans were invincible in colder areas where the growing season was short and their superior diet gave them the greatest advantage.

Professors Cochran and Harpending point out that there was yet another independent development of lactose tolerance, which took place on the Arabian Peninsula among drinkers of camel milk. They suspect that the same results — good diet, mobility, a tradition of raiding — helped the Arabs achieve their remarkable sweep across North Africa and into Europe that was stopped only in 732 — by other milk drinkers.

Germ warfare

A less speculative subject the authors treat at length is the evolution of resistance to disease. It is well known that diseases for which the Indians had no immunity helped the Spanish conquer the New World, and The 10,000 Year Explosion explains why the Indians were so vulnerable. Their ancestors crossed the land bridge from Asia some 15,000 years before the Spanish showed up, and did not bring with them the crowd diseases that sprang up after the rise of agriculture. Also, they passed through cold areas on their way to the Americas, and this killed off many infectious bacteria. Finally, they exterminated most of the large animals in the Americas (which had evolved independently of man and had not developed defenses against hunters), and thus had very few domesticated animals from which they could catch diseases. There was therefore little pressure on Indians to develop strong immune systems.

What is more, during the period when Europeans were being winnowed by plague and pestilence, Indians were probably evolving weaker immune systems. Indeed, they have lower rates than Europeans of type 1 diabetes and multiple sclerosis, which are caused by overactive immune responses.

The Indians’ first contact with Old-World diseases was devastating. Caribbean island tribes were even more vulnerable than those on the mainland, and the Arawak and the Taino were almost completely wiped out. It was Indians in the high Andes who best resisted the Spanish because the invading bacteria often did not survive in the cold, and because Indians were better adapted than Europeans to the thin air.

There are no precise records of early death rates, but more recent epidemics give us an idea. An 1827 smallpox outbreak among Mandan Indians in what later became North Dakota killed 1,475 out of 1,600. The Surui, a small Brazilian rain forest tribe, first made contact with outsiders in 1980. Six years later, despite the efforts of modern medicine, 600 of 800 were dead, mostly of tuberculosis.

Professors Cochran and Harpending point out that it is wrong to accuse the Spanish colonizers of deliberately eliminating native populations. They note that the conquistadors wanted to rule over a populous empire, not a wasteland of corpses. Moreover, when the Spanish conquered the Philippines less then a century later, there was no sharp drop in the population, because Filipinos had resistance to European diseases.

The authors also explain that when Europeans first explored Africa they, too, were decimated by unfamiliar diseases. British soldiers in the Gold Coast could expect to lose half their number in a year. Without the development of medicines for malaria, yellow fever, and sleeping sickness, the colonization of Africa would have been impossible.

On an entirely different subject, The 10,000 Year Explosion has a long chapter that proposes an explanation for how Ashkenazi Jews became the smartest people in the world. Trading and money-lending were high-IQ jobs, and in 1,000 years, or about 40 generations, European Jews appear to have increased their average IQs by about 12 points.

Jewish intelligence seems to be genetically associated with such diseases as Tay-Sachs, Gaucher’s, and familial dysautonomia, which are up to 100 times more common among Jews than European gentiles. People with one copy of these genes appear to have an IQ advantage whereas two copies cause the disease. Professors Cochran and Harpending write that over time, advantageous mutations with such dangerous side effects are usually replaced by more benign mutations. The persistence of these odd mutations in Jews suggests they are recent.

One highly speculative but stimulating chapter considers the possibility that Neanderthals might have made crucial genetic contributions to Homo sapiens. There is no doubt that something important happened 30 to 40 thousand years ago. New tools, improved weapons, art, sculpture, and more efficient use of fire made big changes in what was still a Stone Age existence. These changes took place only in Eurasia — nowhere else — and Professors Cochran and Harpending are convinced they would not have come about without some important genetic change.

As it happens, this Stone Age flowering took place during the 10,000 years or so during which modern man and Neanderthals competed against each other in the same territory. Neanderthals are gone and we are not, so it is safe to assume Homo sapiens were superior — perhaps in intelligence, language, or resistance to disease. However, the authors believe there must have been genetic mixing with Neanderthals, and explain that even if just a few Neanderthal genes were useful to modern man, they would have spread through populations while the useless ones were eliminated. “It is highly likely that out of some 20,000 genes, at least a few of theirs [Neanderthal’s] were worth having,” they write. The authors concede that the genetic evidence is inconclusive — Neanderthal DNA is hard to come by — but they cite cases of “introgression,” in which wild species have acquired useful mutations from other populations.

Readers will have to judge the case for Neanderthal introgression for themselves, but it is typical of the free-wheeling thinking that makes The 10,000 Year Explosion such a pleasure to read. Professors Cochran and Harpending follow the data wherever they lead, which means they cheerfully trample basic assumptions on which the mainstream worldview depends.

This book is therefore yet more proof that science is always the ally of race realism. The better we understand the genome, the more irrefutable our views become. Scientists, along with anyone who cares about the truth, increasingly take it for granted that populations differ not just in susceptibility to disease and reactions to drugs but in average IQ, typical personality, and the ability to achieve civilization. The real question is when, after decades of suppression, sensible views of race will again influence policy. By blowing yet another great hole in today’s poisonous orthodoxy, Gregory Cochran and Henry Harpending have hastened that day.