Race (biology)

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.

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 at least breeds, of animals. 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 such as particular sequences of nucleotides in DNA, even if those sequences do not code for proteins, as genes do.