A start for population genomics

摘要

The most thorough analysis yet of the divergence of sequences in human mitochondrial DNA has been carried out. The results support the view that modern humans originated in Africa. When and where did our species arise? Over the past two decades molecular evolutionists have vigorously pursued this question. DNA evidence from the cell powerhouse known as the mitochondrion has figured prominently in these studies, with mutations providing the raw data for producing evolutionary trees and molecular clocks to time sequence divergence. The mitochondrial family tree of humans has suggested that our roots lie in Africa, but this tree has had only weak statistical support. Conversely, other researchers have proposed that modern humans arose simultaneously in different regions of the world.