NEW YORK (GenomeWeb News) - Human evolution has accelerated dramatically in the last 40,000 years, according to a group of paleoanthropology and genomics researchers who recently analyzed data from the International HapMap Project.
In a study published this week in the Proceedings of the National Academy of Sciences, a team led by John University of Wisconsin, Madison, anthropologist John Hawks propose that the culture, population growth, and geographic dispersion of modern Homo sapiens has accelerated human evolution in striking ways.
Specifically, they note that positive selection in the past 5,000 years has occurred at a rate around 100 times higher than any other period of human evolution.
The scientists focused on linkage disequilibrium, or spots on the genome where genetic variations occur more often than they would by chance.
The study idenfied long, uninterrupted blocks of DNA base pairs -- across tens or hundreds of kilobases -- that might indicate recent positive selection. Using this approach, the investigators found evidence of recent selection on around 1,800 genes, or around 7 percent of the genome.
In the paper, the researchers say that this number of “ascertained selected variants” is surprising because “in theory, such strongly selected variants should be rare.”
“The observed distribution seems to reflect an exceptionally rapid rate of adaptive evolution,” the authors note in the paper.
Some of the data from the ASVs aligns with anthropological observations, the study suggests, citing “rapid skeletal and dental evolution in human populations and the appearance of many new genetic responses to diets and disease,” that have occurred over the past 10,000 years.
Many of these changes in the genome appear to be linked to changes in diet arising with alongside the arrival of agriculture, and for resistance to epidemic diseases that arrived after the beginnings of civilization.
“We are more different genetically from people living 5,000 years ago than they were different from Neanderthals,” Hawks said in a statement.