Modern Genes Reveal 100 Major Population Shifts In Human History

02-18-2014 • http://www.popsci.com, By Francie Diep

Violence and love, conquest and assimilation, they're all in your DNA. Literally. As human populations have moved around the world, they've left bits of their genes to mark their passage.

We've reported on this before, as scientists have used genes to trace immigrations in the Caribbean and the Indian subcontinent. Now, an ambitious new project has attempted to use genetics to identify many of the major movements of humans over the last 4,000 years. No problem, right?

The New York Times has a nice graphic showing how genes are able to trace populations. When two populations meet, they tend to mix genes. If two populations met recently, the pieces of DNA they inherit from one another tend to be large. If they met generations ago, then the pieces of DNA they inherit from each other are smaller.

By measuring the sizes of different chunks of DNA in modern people, a team of geneticists and statisticians from the U.K. and Germany identified more than 100 major population movements. They saw the spread of Mongol genes across the Mongol empire, the appearance of European genes in Maya and Pima Indians during colonization, and the arrival of Cambodian genes at the fall of the Khmer empire.