Every human gene typically comes in a few different possible versions, and researchers are using ancient human DNA to see which versions became more or less common with time—potentially an indicator that they’re “under selection,” meaning they influenced the odds that a person stayed alive to reproduce.
One clear signal that pops out of ancient European genes is a trend toward lighter skin—which makes it easier to produce vitamin D in the face of diminished sunlight and a diet based on grains.
Ancient human DNA uncovered in Europe tells a broad-brush story of three major migrations starting about 45,000 years ago.
First to come out of Africa were hunter-gatherers who dispersed around the continent, followed by farmers who spread out of Anatolia starting 11,000 years ago.
Last came a sweeping incursion of people (and genes) from the plains of modern Ukraine and Russia—animal herders known as the Yamnaya, who surged into Western Europe, spreading the roots of the Indo-European languages now spoken from Dublin to Bombay.