There is no such thing as race.
Biologists have found no genetic similarity between people who have been grouped as races because of their skin pigmentation. Human blood types have no correlation with racial groupings based on skin pigmentation. Humans with different ethnic characteristics, including skin pigmentation, are capable of interbreeding. Most Americans who are descended from slaves have some European ancestry.
Skin pigmentation is a product of the geographic origin of a persons ancestors. People whose ancestors lived for many generations in tropical climates will tend to develop darker skin pigmentation as a biochemical defense mechanism against exposure. People whose ancestors lived in forested regions with seasonal cold and snow will tend to be more pale.
History shows that all major language groups in the world show evidence of large scale migrations throughout history. Language groups were created by trade between peoples who lived in geographic proximity to each other. There are many genetic characteristics which transcend language families. This is because most groups have interbred with other groups to a great enough degree to share these traits across ethnic, cultural or linguistic barriers.
