Edited sentence: Because the genetic difference between any two random individuals is roughly the same, a few traits such as skin color and appearance are arbitrary ways to classify race.Black people were largely defined by their dark skin and sometimes frizzy hair.Breakthroughs in genetics and the mapping of the human genome in the late twentieth century have helped dispel many of the earlier myths about race.Coon believed the different races to have evolved separately over millions of years and that racial differences were thus extremely significant.Eighty-five percent of all genetic variation lies within any local group.However there is still much controversy regarding the interpretation of these small differences.Identical twins, but not fraternal twins, are an exception as the their DNA is a 100% match.In the early twentieth century many scientists held the view that biologically distinct races existed.Ninety-nine point nine percent of any one person's DNA is exactly the same as any other person regardless of ethnicity.Of the remaining 0.1% variation, there is an 8% variation between ethnic groups within a race, such as between the French and the Dutch.Only 7% of all human genetic variation lies on average between major human races such as those of Africa, Asia, Europe, and Oceania.Some scholars argue that even though there is more variation within a population than between populations, the small between-population variation may have implications in medical science.Some scientists such as Carleton S.The belief at that time was that not only did the races differ in appearance but in behavior, intellect and origins.The races corresponded to the major continental regions of Africa, Europe,  Asia and the Americas.There is general agreement among biologists that human racial differences are too small to qualify races as separate sub-species.These races were distinguished from each other based on a few visible traits such as skin color and hair texture.Thus there is more genetic variation within a race than between the various "races".Today most scholars have abandoned these views and see race as a social construct with no biological basis