Book review: La génétique et la question des races, (Genetics and the question of races) by Bertrand Jordan. Published by Editions du Seuil, 2008, 230 pages.
“Ordinary” racism distinguishes several races within the human race, and affirms the superiority of one of them (usually the white race) over the others. This racism has been used to “justify” social inequalities and colonial domination.
It resulted in the genocide against the Amerindians, the Nazi genocide against the Jews and Gypsies, and the ethnic exterminations in Africa... Since 1945, all of the declarations of the rights of man have proclaimed that all men are equal in rights, and in France, racism is not an opinion – it is a crime.
In this book, which is both accessible to the general public and very informative, biologist Bertrand Jordan repeats that no scientific backing can be found for racist ideas. Since the 1970s, geneticists have formally rejected the very notion of races among human beings. Their work has demonstrated that the genetic variability within a supposed race (whether it be white, yellow or black) is greater than the variability between any one “race” and another. In other words, genes have no race.
Moreover, it is impossible to know whether the dissimilarities observed between two human “races” is due to heredity or to the socio-cultural milieu. The complete sequencing of the three billion bases of the DNA of human chromosomes in 2003 showed that two human beings, chosen at random among the six billion inhabitants of the earth, share 99.9% of their DNA. We are all descended from a few thousand African ancestors, and over the past hundred thousand years the migrations and intercourse among human populations have been continual.
Nevertheless, the 0.1% of difference between two individuals represents three million different bases in their respective DNA, all the same. The analysis of the DNA of a great many individuals has shown that this variability is mainly due to “isolated” changes (or snips) involving a single base. These snips are mostly to be found in the non-coding areas of DNA and play no hereditary role. However a few do affect genes, and they determine, for example, skin color or sensitivity to diabetes.
Since 2004, DNA chips have made possible the rapid analysis of thousands of snips from hundreds of subjects. These analyses have confirmed that there are no genetically isolated human “races.” But an in-depth examination of carefully-chosen sets of snips has shown that the DNA of any individual can be associated with large geographic groups: African, European, Asian, Amerindian, Afro-American... For example, one may analyze the proportion of different ancestral components in the population of the United States.
There are significant variations in the frequency of some diseases among human groups of different ancestry. Most of the time, these variations are not due to heredity but to the environment. It is also conceivable that some aptitudes – physical or cognitive – vary depending on ancestor groups, but such “innate” variations between groups have never been demonstrated as yet. On the other hand, genetic variations within the human race have made it possible for humanity to survive climate crises and plague and cholera epidemics.
