A Troublesome Inheritance: Genes, Race, and Human History

Geographically isolated populations of a species (unable to interbreed with others of their kind) will be subject to natural selection based upon their environment. If that environment differs from that of other members of the species, the isolated population will begin to diverge genetically, as genetic endowments which favour survival and more offspring are selected for. If the isolated population is sufficiently small, the mechanism of genetic drift may cause a specific genetic variant to become almost universal or absent in that population. If this process is repeated for a sufficiently long time, isolated populations may diverge to such a degree they can no longer interbreed, and therefore become distinct species.None of this is controversial when discussing other species, but in some circles to suggest that these mechanisms apply to humans is the deepest heresy. This well-researched book examines the evidence, much from molecular biology which has become available only in recent years, for the diversification of the human species into distinct populations, or “races” if you like, after its emergence from its birthplace in Africa. In this book the author argues that human evolution has been “recent, copious, and regional” and presents the genetic evidence to support this view.A few basic facts should be noted at the outset. All humans are members of a single species, and all can interbreed. Humans, as a species, have an extremely low genetic diversity compared to most other animal species: this suggests that our ancestors went through a genetic “bottleneck” where the population was reduced to a very small number, causing the variation observed in other species to be lost through genetic drift. You might expect different human populations to carry different genes, but this is not the case—all humans have essentially the same set of genes. Variation among humans is mostly a result of individuals carrying different alleles (variants) of a gene. For example, eye colour in humans is entirely inherited: a baby's eye colour is determined completely by the alleles of various genes inherited from the mother and father. You might think that variation among human populations is then a question of their carrying different alleles of genes, but that too is an oversimplification. Human genetic variation is, in most cases, a matter of the frequency of alleles among the population.This means that almost any generalisation about the characteristics of individual members of human populations with different evolutionary histories is ungrounded in fact. The variation among individuals within populations is generally much greater than that of populations as a whole. Discrimination based upon an individual's genetic heritage is not just abhorrent morally but scientifically unjustified.Based upon these now well-established facts, some have argued that “race does not exist” or is a “social construct”. While this view may be motivated by a well-intentioned desire to eliminate discrimination, it is increasingly at variance with genetic evidence documenting the history of human populations.Around 200,000 years ago, modern humans emerged in Africa. They spent more than three quarters of their history in that continent, spreading to different niches within it and developing a genetic diversity which today is greater than that of all humans in the rest of the world. Around 50,000 years before the present, by the genetic evidence, a small band of hunter-gatherers left Africa for the lands to the north. Then, some 30,000 years ago the descendants of these bands who migrated to the east and west largely ceased to interbreed and separated into what we now call the Caucasian and East Asian populations. These have remained the main three groups within the human species. Subsequent migrations and isolations have created other populations such as Australian and American aborigines, but their differentiation from the three main races is less distinct. Subsequent migrations, conquest, and intermarriage have blurred the distinctions between these groups, but the fact is that almost any child, shown a picture of a person of European, African, or East Asian ancestry can almost always effortlessly and correctly identify their area of origin. University professors, not so much: it takes an intellectual to deny the evidence of one's own eyes.As these largely separated populations adapted to their new homes, selection operated upon their genomes. In the ancestral human population children lost the ability to digest lactose, the sugar in milk, after being weaned from their mothers' milk. But in populations which domesticated cattle and developed dairy farming, parents who passed on an allele which would allow their children to drink cow's milk their entire life would have more surviving offspring and, in a remarkably short time on the evolutionary scale, lifetime lactose tolerance became the norm in these areas. Among populations which never raised cattle or used them only for meat, lifetime lactose tolerance remains rare today.Humans in Africa originally lived close to the equator and had dark skin to protect them from the ultraviolet radiation of the Sun. As human bands occupied northern latitudes in Europe and Asia, dark skin would prevent them from being able to synthesise sufficient Vitamin D from the wan, oblique sunlight of northern winters. These populations were under selection pressure for alleles of genes which gave them lighter skin, but interestingly Europeans and East Asians developed completely different genetic means to lighten their skin. The selection pressure was the same, but evolution blundered into two distinct pathways to meet the need.Can genetic heritage affect behaviour? There's evidence it can. Humans carry a gene called MAO-A, which breaks down neurotransmitters that affect the transmission of signals within the brain. Experiments in animals have provided evidence that under-production of MAO-A increases aggression and humans with lower levels of MAO-A are found to be more likely to commit violent crime. MAO-A production is regulated by a short sequence of DNA adjacent to the gene: humans may have anywhere from two to five copies of the promoter; the more you have, the more the MAO-A, and hence the mellower you're likely to be. Well, actually, people with three to five copies are indistinguishable, but those with only two (2R) show higher rates of delinquency. Among men of African ancestry, 5.5% carry the 2R variant, while 0.1% of Caucasian males and 0.00067% of East Asian men do. Make of this what you will.The author argues that just as the introduction of dairy farming tilted the evolutionary landscape in favour of those bearing the allele which allowed them to digest milk into adulthood, the transition of tribal societies to cities, states, and empires in Asia and Europe exerted a selection pressure upon the population which favoured behavioural traits suited to living in such societies. While a tribal society might benefit from producing a substantial population of aggressive warriors, an empire has little need of them: its armies are composed of soldiers, courageous to be sure, who follow orders rather than charging independently into battle. In such a society, the genetic traits which are advantageous in a hunter-gatherer or tribal society will be selected out, as those carrying them will, if not expelled or put to death for misbehaviour, be unable to raise as large a family in these settled societies.Perhaps, what has been happening over the last five millennia or so is a domestication of the human species. Precisely as humans have bred animals to live with them in close proximity, human societies have selected for humans who are adapted to prosper within them. Those who conform to the social hierarchy, work hard, come up with new ideas but don't disrupt the social structure will have more children and, over time, whatever genetic predispositions there may be for these characteristics (which we don't know today) will become increasingly common in the population. It is intriguing that as humans settled into fixed communities, their skeletons became less robust. This same process of gracilisation is seen in domesticated animals compared to their wild congeners. Certainly there have been as many human generations since the emergence of these complex societies as have sufficed to produce major adaptation in animal species under selective breeding.Far more speculative and controversial is whether this selection process has been influenced by the nature of the cultures and societies which create the selection pressure. East Asian societies tend to be hierarchical, obedient to authority, and organised on a large scale. European societies, by contrast, are fractious, fissiparous, and prone to bottom-up insurgencies. Is this in part the result of genetic predispositions which have been selected for over millennia in societies which work that way?It is assumed by many right-thinking people that all that is needed to bring liberty and prosperity to those regions of the world which haven't yet benefited from them is to create the proper institutions, educate the people, and bootstrap the infrastructure, then stand back and watch them take off. Well, maybe—but the history of colonialism, the mission civilisatrice, and various democracy projects and attempts at nation building over the last two centuries may suggest it isn't that simple. The population of the colonial, conquering, or development-aid-giving power has the benefit of millennia of domestication and adaptation to living in a settled society with division of labour. Its adaptations for tribalism have been largely bred out. Not so in many cases for the people they're there to “help”. Withdraw the colonial administration or occupation troops and before long tribalism will re-assert itself because that's the society for which the people are adapted.Suggesting things like this is anathema in academia or political discourse. But look at the plain evidence of post-colonial Africa and more recent attempts of nation-building, and couple that with the emerging genetic evidence of variation in human populations and connections to behaviour and you may find yourself thinking forbidden thoughts. This book is an excellent starting point to explore these difficult issues, with numerous citations of recent scientific publications.

This reviewer heard much hoopla about what Wade has presented here, before reading the book, much of which charged the author with racism and heaped scorn on the contents as racist demagoguery. After reading the book, I must say that it is unfortunate that so much hysteria was generated, because the charges could not be further from the truth. The book's essential premises, resting on an impressive array of recent data made available by the sequencing of the human genome, is that 1) humans went on evolving in different ways long after they left the African savannah 185,000 years ago and that there is, therefore, a genetic basis to the differentiation of races, and 2) in service to racial politics, increasing scientific data supporting this genetic basis has been routinely suppressed. The purpose of Wade's book, therefore, is not only to present more recent, as well as older evidence that supports a genetic basis to race that goes beyond visible cosmetic differences, but to begin to correct that suppression. Rather than believing him a racist, I think he has done something quite brave with this book.Wade goes to great pains throughout this book to make it clear that a genetic component to race is not an excuse for racism. Anyone who twists the information to serve a racist agenda was probably racist to begin with. As Wade states in his book, opposing racism is a matter of principle, not science, and there is no genetic basis for racism. To reject science in service to social orthodoxy is both dangerous and unproductive. After reading Wade's forthright history and denunciation of the sorry uses to which genetics have (as he makes clear, inaccurately) been put, I believe that those who leaped to accuse Wade himself of racism did not read the book, but jumped to conclusions because they were frightened by the information.The book is thoughtful and thorough about the history of this debate, as well as the history of how humans dispersed, fanned out, developed tribal affiliations, adapted to new environments and succumbed to natural selection and genetic drift, the move from hunter-gatherers to permanent settlements with the discovery of agriculture . . . I realized that I knew far less than I had imagined about "our" story. Wade fills this picture in with great narrative efficiency, and I found myself feeling not only fascinated but oddly proud to be human; after reading about our 200,000 year journey to modernity I could only sense astonishment that we ever did it - we are, all of us, a truly astonishing species and it is a shame that so few reviews mention how Wade brings this out.The chapters containing more nuts and bolts genetics required slow, and occasionally repeat, reading, but eventually they sink in. It is very much worth the effort. This is a wonderful book, and I am so disappointed that so many well-meaning people dismissed it out of ignorance and fear.

If you plan to read this book make sure you get a definition of the genetic component 'allele' first. Understanding this is important for the first couple of chapters.All-in-all a very interesting and useful study of some of the implications arising from the fledgling science of genome analysis. This is just the beginning but already it seems that many left-wing pundits are rattled – some of the one-star reviews posted here are an indication of what might be termed the anxiety of the egalitarians. It goes without saying that any scientific study which may lead to a questioning of left-leaning academic orthodoxy is in danger of gaining taboo status.In fact this book does NOT make a case for genetic determinism. The author argues that more general but significant differences can be seen and studied in the world's major racial groupings – that those minor but important differences probably have a genetic base. It has been assumed that evolution is a very slow process based on the successful adaptation of mutations. Mr Wade makes a case that minor but important changes can evolve in a much shorter time – perhaps as little as five generations. This field of genetic research is still very new but over time it will certainly reveal aspects of human nature that may not comfortably support of everyone's philosophy of mankind.An important part of Mr Wade's thesis is the long term effects of those collective organisations he calls social institutions. Although individual creativity and intelligence are of tremendous importance it is Western institutions which have, over the past 500 years, enabled and encouraged the huge technological and intellectual lead all the world now benefits from. With that in mind, should we be worried that so many of our institutions are now falling under a well-meaning but censorious and restrictive form of moral control loosely labelled 'woke'?

This is wonderfully written wonderful piece of a book. I think every single person should read this excellent book. I don't know the author personally but I am really impressed by the amount of research and hardwork that the author has put in to create this excellent book. He has thrown light on a very fundamental yet controversial issue .The author's approach to the issue of race and culture has remained unbiased and forthright.

Great read. A fresh perspective for anyone who has a genuine interest in human evolution. You'll find yourself agreeing with more than you thought.

Now that I've finished this excellent book, I'd love to lend this out to people. Unfortunately, we live in a world where the subject itself is so taboo that once can not even discuss concept of race. This is a shame. This book makes the world a more interesting and comprehensive place. It also leads to greater understanding of those in various cultural / ethnic groups. Very stimulating. True diversity is accepting and celebrating our differences.

I had been looking for a new approach to race and to racism. One that could show that human and animal traits follow genetics; being races the result of such. To me, it has nothing to do with racism. I think it is possible to be against racism and also understand that races existed in the past.The book is very good, even excelent in all aspects, including readability.