Who We Are and How We Got Here Review

By John Engelman

The message of Who We Are and How We Got Here, by David Reich, is that we are the descendants of men who killed their enemies and took their land. That is how we got here. Sometimes our ancestors kept the females of their enemies as concubines. Sometimes they annihilated them too.

Because I am a kind hearted guy I do not like thinking that my ancestors would do that. I never would. I am sure Dad never did. Unfortunately, we cannot choose our ancestors. We cannot improve their behavior.

The big picture about human evolution is that it began in Africa about six million years ago when the Rift Valley developed, splitting the common ancestor of humans and chimpanzees. The chimps got the better half of the deal. Chimps like to eat leaves and fruit. They found these abundantly in the jungle areas they lived in. Our ancestors had to hustle to survive. The half they got dried up into areas that are grasslands to this day in eastern Africa.

The first distinctly human characteristic that evolved was the human foot and the ability to walk upright. Chimpanzee feet resemble their hands. They can manipulate objects with their feet. We cannot. They cannot walk upright for long distances.

After our ancestors evolved the ability to walk upright their brains began to grow, indicating the evolution of more intelligence. They could not run fast enough to catch the game animals they learned to eat. They could not outrun the carnivorous animals for whom they were game. They also lacked long and sharp teeth and claws. They had to learn how to use sticks and rocks as weapons. Eventually these became stone tipped spears and hatchets.

From time to time, beginning about 2.8 million years ago, a small number of humans left Africa, and spread. Nevertheless, human evolution was moving faster in Africa for two reasons. First, the number of humans in Africa was far greater than the number of humans out of Africa. Large populations usually evolve faster than small populations, because there is more scope for beneficial mutations to develop and spread.

Second, the inhabitants of Africa had more genetic diversity. This is a characteristic Negroes retain to the present. More genetic diversity enables a population to evolve faster in any direction. The alleles it needs are already present. An allele is a variation of a gene.

When the next small group of humans left Africa it encountered the descendants of the previous group. Because it had evolved more intelligence it “displaced” (i.e., annihilated) the previous group. It was able to do so because it had evolved more intelligence. Nevertheless, some interbreeding occurred.

In recent years scientists have developed the ability to trace the migrations, mergers, and displacements of prehistoric humans by studying DNA from living humans and the remains of prehistoric humans. David Reich is a professor at Harvard, and a pioneer in this field.

About four to six hundred thousand years ago the ancestors of Neanderthals left Africa, and populated the Near East and Europe, where they continued to evolve. Meanwhile modern humans appeared in Africa slightly more than 100,000 years ago. These modern humans had physical dimensions that correspond to the physical dimensions of contemporary humans. The archaic humans did not. About 50,000 years ago one hundred to several hundred of these modern humans left Africa. About 35,000 years ago these modern humans, who for over a century have been called “Cro Magnons,” entered Europe. In several thousand years they displaced the Neanderthals. Again, there was some interbreeding.

About 8,000 years ago the displacers were displaced by Neolithic farmers spreading out from the near east, where farming originated.

Here I must tepidly disagree with the distinguished Harvard professor. He claims that the Paleolithic hunters the Neolithic farmers found in Europe had blue eyes, and dark skin.

Although blue eyes are sometimes found in Caucasians, they are rare in the entire human species. I cannot understand what population pressures would have caused all of the Paleolithic hunters, whose ancestors had displaced the Neanderthals, to develop blue eyes.

Here I agree with Utah University Professors Gregory Cochran and Henry Harpending who wrote in The 10,000 Year Explosion: How Civilization Accelerated Human Evolution, that blue eyes developed from a single mutation in a single European about 6,000 to 10,000 years ago. Cochran and Harpending speculate that blue eyes spread because people with blue eyes were considered to be more attractive, so they had an easier time finding mates.

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Cochran and Harpending do consider the possibility that the hunters of Europe had dark skin. They reason that dark skinned hunters would not get rickets, because fresh meat is rich in vitamin D. It was only with the use of agriculture - which reduced the consumption of fresh meat - in northern climates that skin became lighter to use the sun to develop vitamin D.

This is an interesting theory, but for two problems. First, with the exception the liver of certain mammals, fresh meat is not a natural source of vitamin D. Second, there is no reason to believe that the ancestors of the Eskimos ever practiced agriculture. Nevertheless, they have light skin.

So, again I disagree with the Harvard professor. This disagreement is important, because Professor Reich claims that the genetic differences between the Paleolithic hunters and the Neolithic farmers who displaced them were as different as between contemporary Europeans and Han Chinese. I think they were both recognizably Caucasian. This is an issue that will be resolved as more is leaned from DNA analysis.

We do not need to guess about the race of the Neolithic farmers. Their descendants continue to live on the Mediterranean island of Sardinia in a genetically undiluted form. They resemble Italians and Greeks.

Nevertheless in the rest of Europe they were displaced (again I mean “annihilated”) by herding people from the Russian steppes north of the Black Sea and the Caspian Sea. These were the people – and here I agree with Professor Reich – who settled Europe, Iran, and India, spreading Indo European languages.

The advantages these pastoral people had over the Neolithic farmers were the facts that they had domesticated the horse, and invented the wheel and wheeled wagons. These gave them greater mobility. They may also have carried an ancestor of bubonic plague, to which they had resistance, while the Neolithic farmers did not.

At any rate, these herders from the Russian steppes were not displaced. Their descendants still live there. Comparing them with the inhabitants of Sardinia we can see that they both belong to the Caucasian race, although Professor Reich is uncomfortable with the use of the word “race.” That discomfort is the reason I give this fascinating book a four star rating, rather than a five star rating.

Professor Reich tries to straddle the divide between those who claim, “Race is only a social construct,” and those who claim that the white race is superior to the other races. By “white” those in the second group exclude non European Caucasians, and even Ashkenazi Jews, although the Ashkenazim have lived in Europe for about two thousand years.

To the first group he says with more hesitation than I have when disagreeing with him, “the orthodoxy that has emerged over the last century – the idea that human populations are all too closely related to each other for there to be substantial average biological differences between them – is no longer sustainable.”

To the second group he claims that what are considered to be the three main races of Caucasians, Mongloids, and Negroes are did not exist until more than about 10,000 years ago, but that they are the more recent results of migrations and mixtures.

The more plausible theory I have encountered elsewhere – one again based on DNA differences - is that the difference between Negroes and everyone else is about 50,000 years old, and that the split between Caucasians and Mongoloids happened about thirty thousand years ago.

In the third part of his book Professor Reich makes assertions, which I suspect were motivated more by a desire to maintain harmonious relationships with other Harvard professors than by a desire to follow the facts wherever they lead. For example, he calls Professors Cochran, Harpending, Nicholas Wade, the author of A Troublesome Inheritance: Genes, Race, and Human History,

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and Nobel Laureate James Watson “racists” for their willingness to go further than he is in making assertions about human genetics that are either known or highly probable.

Oh well. It is Professor Reich’s life, his academic career, and his position on invite lists to fashionable dinner parties. He has written a fascinating book.

I look forward to the day when he and other geneticists have less reason to fear the constraints of political correctness.