Category Archives: Transhuman News

Opinion The Weekend Read Illustration by Umberto Mischi for TIME The New York Times' former science editor on research showing that evolution didn't stop when human history began.

A longstanding orthodoxy among social scientists holds that human races are a social construct and have no biological basis. A related assumption is that human evolution halted in the distant past, so long ago that evolutionary explanations need never be considered by historians or economists.

New analyses of the human genome have established that human evolution has been recent, copious, and regional.In the decade since the decoding of the human genome, a growing wealth of data has made clear that these two positions, never at all likely to begin with, are simply incorrect. There is indeed a biological basis for race. And it is now beyond doubt that human evolution is a continuous process that has proceeded vigorously within the last 30,000 years and almost certainly though very recent evolution is hard to measure throughout the historical period and up until the present day.

New analyses of the human genome have established that human evolution has been recent, copious, and regional. Biologists scanning the genome for evidence of natural selection have detected signals of many genes that have been favored by natural selection in the recent evolutionary past. No less than 14% of the human genome, according to one estimate, has changed under this recent evolutionary pressure.

Analysis of genomes from around the world establishes that there is a biological basis for race, despite the official statements to the contrary of leading social science organizations. An illustration of the point is the fact that with mixed race populations, such as African Americans, geneticists can now track along an individuals genome, and assign each segment to an African or European ancestor, an exercise that would be impossible if race did not have some basis in biological reality.

Racism and discrimination are wrong as a matter of principle, not of science. That said, it is hard to see anything in the new understanding of race that gives ammunition to racists. The reverse is the case. Exploration of the genome has shown that all humans, whatever their race, share the same set of genes. Each gene exists in a variety of alternative forms known as alleles, so one might suppose that races have distinguishing alleles, but even this is not the case. A few alleles have highly skewed distributions but these do not suffice to explain the difference between races. The difference between races seems to rest on the subtle matter of relative allele frequencies. The overwhelming verdict of the genome is to declare the basic unity of humankind.

Human evolution has not only been recent and extensive, it has also been regional. The period of 30,000 to 5,000 years ago, from which signals of recent natural selection can be detected, occurred after the splitting of the three major races, so represents selection that has occurred largely independently within each race. The three principal races are Africans (those who live south of the Sahara), East Asians (Chinese, Japanese, and Koreans), and Caucasians (Europeans and the peoples of the Near East and the Indian subcontinent). In each of these races, a different set of genes has been changed by natural selection. This is just what would be expected for populations that had to adapt to different challenges on each continent. The genes specially affected by natural selection control not only expected traits like skin color and nutritional metabolism, but also some aspects of brain function. Though the role of these selected brain genes is not yet understood, the obvious truth is that genes affecting the brain are just as much subject to natural selection as any other category of gene.

Human social structures change so slowly and with such difficulty as to suggest an evolutionary influence at work.What might be the role of these brain genes favored by natural selection? Edward O. Wilson was pilloried for saying in his 1975 book Sociobiology that humans have many social instincts. But subsequent research has confirmed the idea that we are inherently sociable. From our earliest years we want to belong to a group, conform to its rules and punish those who violate them. Later, our instincts prompt us to make moral judgments and to defend our group, even at the sacrifice of ones own life.

Anything that has a genetic basis, such as these social instincts, can be varied by natural selection. The power of modifying social instincts is most visible in the case of ants, the organisms that, along with humans, occupy the two pinnacles of social behavior. Sociality is rare in nature because to make a society work individuals must moderate their powerful selfish instincts and become at least partly altruistic. But once a social species has come into being, it can rapidly exploit and occupy new niches just by making minor adjustments in social behavior. Thus both ants and humans have conquered the world, though fortunately at different scales.

Conventionally, these social differences are attributed solely to culture. But if thats so, why is it apparently so hard for tribal societies like Iraq or Afghanistan to change their culture and operate like modern states? The explanation could be that tribal behavior has a genetic basis. Its already known that a genetic system, based on the hormone oxytocin, seems to modulate the degree of in-group trust, and this is one way that natural selection could ratchet the degree of tribal behavior up or down.

Read the rest here:
What Science Says About Race and Genetics

Nicholas Wade, a leading science writer whose specialty is human evolution, likes to ask interesting questions. Here are some examples:

Why has the West been the most exploratory and innovative civilization in the world for the past 500 years?

Why are Jews of European descent so massively overrepresented among the top achievers in the arts and sciences?

Why is the Chinese diaspora successful all around the world?

Why is it so difficult to modernize tribal societies?

Why has economic development been so slow in Africa?

Contemporary thinkers have offered lots of provocative answers for such questions. Its all about geography. Or institutions. Or rice culture. Or the devastating legacy of colonialism. Or Jewish mothers. Now comes another explanation, one that bravely explores the highly dangerous elephant in the room. Mr. Wade argues that human history has also been profoundly influenced by genetics.

Part of his new book, A Troublesome Inheritance: Genes, Race and Human History, is a summary of new findings in genetic science, and part of it is highly speculative. All of it is bound to be deeply unpopular among social scientists, because it challenges their entrenched belief that race is nothing more than a social construct. The wide diversity in human societies around the world can be explained entirely by culture, they insist. Were all the same under the skin.

Except were not quite. Since the sequencing of the human genome in 2003, evidence of subtle genetic differences has been piling up. As our ancestors branched out of Africa, different groups of people evolved in slightly different ways to adapt to local conditions. The most successful of those people passed on their adaptations to their offspring. The variations in human DNA correspond quite precisely to what we think of as the major races. They are associated not just with differences in hair and skin colour, but also with a range of other physical and (probably) behavioural traits. Another astonishing fact is that 14 per cent of the human genome has been under natural selection strong enough to be detectable. The evidence also shows that evolution can proceed remarkably quickly, and has never stopped. (The Tibetan adaptation to high altitudes is just 3,000 years old.) Human evolution has been recent, copious and regional, Mr. Wade says in his book.

Mr. Wade knows he may be stepping on a land mine. In the not so distant past, ideas about racial difference have been used to justify everything from slavery to extermination. A lot of people think its safer to deny such differences exist. The subject is so taboo that any discussion of racial differences is widely considered tantamount to racism itself. Geographer Jared Diamond (author of Guns, Germs and Steel, which contends that geography explains everything) has said that only people capable of thinking the Earth is flat believe in the existence of human races. So that makes Mr. Wade, who has written for The New York Times for 20 years, either foolhardy or fearless. The idea that human populations are genetically different from one another has been actively ignored by academics and policy makers for fear that such inquiry might promote racism, he writes.

See the original post here:
What if race is more than a social construct?