Blake Griffin

John 8:32 says:

“What Does DNA Say?”, race is defined primarily by skin color. Since that’s a genetic trait, the logic goes, race itself must be genetic, and there must be differences that are more than skin deep.

But that’s not what modern genetics reveals. Quite the contrary, it shows that race is truly skin deep. Indeed, genetics undermines the whole concept that humanity is composed of ”races”—pure and static groups that are significantly different from one another. Genetics has proven otherwise by tracing human ancestry, as it is inscribed on DNA.

After, analyzing something called mitochondrial DNA. Almost all human cells contain tiny bacteria-like entities called mitochondria. They provide energy to cells, and they have their own DNA, separate from the DNA that actually makes a person. Mitochondria are not in sperm cells; therefore, they are inherited only from the mother. They record a person’s matrilineal heritage.

The paternal counterpart is the Y chromosome. Women, of course, lack the Y chromosome, so it is inherited strictly from father to son. It can be quite revealing to trace how the Y chromosome and mitochondrial DNA mix in a single population. Under the old South African apartheid categories, ”colored” people were those who descended from black and white parents—but their Y chromosome almost always shows a European ancestry, whereas their mitochondrial DNA usually shows an African heritage. To put it plainly, white men were sleeping with black women, but black men were not sleeping with white women.

But sometimes only DNA can settle questions of human history.

Two million years ago, various hominid ancestors of modern humans migrated out of Africa. Neanderthals settled in Europe–and some scientists argued that Europeans descend from Neanderthals, Asians from other hominids such as Peking Man or Java Man, and Africans from still other sources. Genetics has helped demolish this ”multiregional” theory.

Mitochondrial DNA indicates that all living humans descend from one maternal source—christened Mitochondrial Eve—who lived in Africa between 100,000 and 200,000 years ago. Similarly, the Y chromosome shows that all men have a common ancestor, Y-chromosome Adam, who lived at the same time. (Actually, both analysis indicate that modern humans descend from a small founding population of about 5000 men and an equal number of women.)

Did modern humans coming out of Africa completely replace Neanderthals and the other earlier hominids—or did they interbreed with them? This year, Stoneking and researchers in Germany compared the mitochondrial DNA of modern humans to that of a Neanderthal skeleton between 30,000 and 100,000 years old. The conclusion: Neanderthals contributed nothing to human maternal ancestry.”

For example, light skin color is needed in northern climates for the sun’s ultra- violet light to penetrate into the body and transform vitamin D into a usable form. This mutation may well have arisen at different times, in different ancestral groups, on different points along the DNA. That’s true for cystic fibrosis, which occurs almost exclusively in people of European descent but is caused by several different mutations.

In other words, ”white people” do not share a common genetic heritage; instead, they come from different lineages that migrated from Africa and Asia. Such mixing is true for every race. ”All living humans go back to one common ancestor in Africa,”

Over time, ”genetics will help beat down racist arguments,” says Eric Lander, a world-renowned geneticist at M.I.T.