Study finds humans still evolving, and quickly

Plaster casts of skulls, from left to right, of the earliest fossil finds of humanoids to modern man at the National Museum of Kenya in Nairobi, November 8, 2007. (Stephen Morrison / EPA / November 8, 2007)

The pace has been increasing since people started spreading through Europe, Asia and Africa 40,000 years ago.

By Karen Kaplan

Los Angeles Times Staff Writer

December 11, 2007

The pace of human evolution has been increasing at a stunning rate since our ancestors began spreading through Europe, Asia and Africa 40,000 years ago, quickening to 100 times historical levels after agriculture became widespread, according to a study published today.

By examining more than 3 million variants of DNA in 269 people, researchers identified about 1,800 genes that have been widely adopted in relatively recent times because they offer some evolutionary benefit.

Until recently, anthropologists believed that evolutionary pressure on humans eased after the transition to a more stable agrarian lifestyle. But in the last few years, they realized the opposite was true -- diseases swept through societies in which large groups lived in close quarters for a long time.

Altogether, the recent genetic changes account for 7% of the human genome, according to the study published in the Proceedings of the National Academy of Sciences.

(Original here.)