Race: An ethnic stock or division of humans. Naturalists and ethnographers have long divided humans into a variable number of distinct races. However, DNA and other genetic studies have revealed that that most genetic variation, about 94%, is within so-called racial groups while these racial groupings differ from one another only in about 6% of their genes. This means that there is greater genetic variation within racial groups than between them. The concept of race is a superficial and subjective one. All of humankind is a single species.