Vast number of human DNA variants arose only in the past 5,000 years
A new look at living people’s DNA reveals that the human genome just isn’t what it was in Neolithic times.
Most of the genetic quirks people carry today popped up within the last 5,000 years or so, researchers report online November 28 in Nature. Human populations exploded from no more than a few million to 7 billion, thanks largely to the rise of agriculture.
Researchers examined more than 15,000 genes in each of 6,515 people of European-American or African-American ancestry, looking for genetic variants. Previously, the team reported finding a plethora of rare genetic variants in a smaller sample. Now, the researchers have been able to date when most of the variants arose.
Of the 709,816 genetic variants found in European-Americans in the study, more than 81 percent arose in the past 5,000 years, the researchers determined. African-Americans in the study collectively carried 643,128 genetic variants, more than 58 percent of which are