Race (biology)

See race for a more general treatment of the concept of human races, and see subspecies for the concept of "race" as applied to all species; the following article concerns how biologists have approached human races.

Races of humans have been delineated by many cultures over human history. After the fact, once these racial groups had already been described on a social and cultural basis, biologists and physicians have studied them from a genetic and medical perspective.

The term, "race" in biology has several meanings- some are used only infrequently or in certain contexts. In the 19th century, and before, the word "race" was often used in biology as a synonym for a kind or kindred of creature or plant, and the term race was applied to all living things to describe both species and relatives of an individual living thing. For example, the full title of one of Charles Darwin's books, published in 1859, is "On the Origin of Species By Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life." The word race has also been applied to people in a different, non-biologic way, as a kind, or sort, of person- such as "the race of women" or the "race of gamblers", sometimes in a poetic or humorous way. Race, in both biology and popular usage, is often used to designate human ethnic groups. The history of the word "race" used as a designation for ethnic groups in biology has few poetic or humorous associations. Instead, that history is strongly figured in the support of a number of social, health science, and military undertakings that have ranged from Eugenics to The Holocaust, and Apartheid. Particularly since the aftermath of the Holocaust , when the result of the biological thinking that led the Nazi regime to rationalize genocide became clearly understood, there has been a great reluctance within anthropology, medicine, and other field of human biology to approach basic research in these respective fields according to racial ideation. It is difficult to find chapters in current textbooks in these field entitled "Race", for example. That was not true in texts of these disciplines before World War II.

This is a remarkable testament to the impact of social history on biology, because, during this same era, the power of molecular biology and, most particularly, molecular genetics, has been a driving force in biological research and lends itself to the analysis of inherited features and the biology of kindreds. In one meaning of the word "race", that is not used technically as a biological term, race refers to all of the descendents of an individual, and in that sense much of modern human genetics has focused on the study of race. Even though these studies have not been generally aimed at comparing the classic races of mankind that were and are popularly acknowleged: Caucasian, Negroid, Mongoloid, there has been so much analysis of kindreds that fall into these groups that it is possible to discuss the findings in terms of race. What has been found out so far, is that there are no qualitative biological differences that correspond to these groups and currently, in human biology , including health science and anthropology, the term race is not held to have any absolute biological meaning outside of explicitly defined kinship groups. Of course, there are biological studies of "whites" and "black", for example, in health sciences; but these are descriptive studies of response to medication, or prevalence of disease, in socially defined groups - often self-defined, and they have the same kind of significance as studies of urban populations, or residents of certain geographic areas; in other words the groups are defined by non-biologica, criteria and then studied for biological characteristics.

Currently, in plants and animals, the word "race" is not a primary designation of type, although it is still used properly as a synonym for "kind" in biology. Instead, when it comes to groups of plants, animals, or microorganisms, that are related by inheritance and share characteristics, the words subspecies, breed, variety, and strains are most frequently and properly used. When discussing human beings, these words have never had any common usage in biology, anthropolgy, or medicine, instead the word "race" has been used preferentially.

Historically, there have been definitions of races that assumed that some racial groups were superior, or more highly evolved, or at least held major biological differences from other racial groups. By the nineteenth century, western biologists grouped human beings into various racial classifications under the assumption that there were distinct biological differences between them, similar to the differences between species, or subspecies. More recently, molecular genetic analysis has shown that there do not appear to be measureable genetic differences according to these classic racial groups. However, when populations of people are related, then they do tend to share certain forms of genes and genetic markers. Some of these markers are particular sequences of nucleotides in DNA that are different in different people, and inherited. These sequences, which include microsatellite DNA, are often so highly variable that they are therefore especially useful for looking for inherited relationships, even though these distinctively variable sequences do not code for proteins, as genes do. Genetic polymorphisms have been used to construct theoretical family trees of man, and to plot historical migrations according to where populations with shared polymorphisms appear. However useful these genetic markers are, they have not revealed the kinds of qualitative differences that were once assumed to be inherent features of human races, tribes, and ethnic groups by eugenecists, sociologists and sociobiological theorists of the past.

Genetic markers of populations

Since the development of PCR and other rapid, powerful DNA chemistry laboratory techniques, there have been multiple investigations of how the frequency of certain sequences vary in different populations. These different forms of DNA are called polymorphisms and, since they vary on an inherited basis, polymorphisms can be useful for tracing the ancestries of populations. For example, in 1966 the Gm ab3st gene was shown to be common in Mongoloid people, including Asians and Native Americans. Since then, four different varieties of the gene, Gm haplotypes, have been described: Gm ag, axg, ab3st, and afb1b3. When individuals have these GM haplotypes, they fall into one of two patterns- " the first is a southern group characterized by a remarkably high frequency of Gm afb1b3 and a low frequency of Gm ag, and the second, a northern group characterized by a high frequency of both Gm ag and Gm ab3st but an extremely low frequency of Gm afb1b3." (Hideo Matsumoto. Characteristics of Mongoloid and neighboring populations based on the genetic markers of human immunoglobulins. Human genetics. Volume 80, Number 3 / November, 1988 207-218). By studying the frequencies of these genes in poulations throughout the world, researchers have concluded that the Japanese race belongs to northern Mongoloids and that the origin of the Japanese race was in Siberia, and most likely in the Baikal area of the Soviet Union. This kind of genetic marker research is fairly typical of racial studies in current biology. In other words, it is possible to make correlations in the historical migration of peoples and gene markers.