Credit: Science Museum of Minnesota, based on the work of Dr. Kenneth Kidd
This image is from the Science Museum of Minnesota, based on the work of Yale geneticist Kenneth Kidd, Ph.D. It shows the distribution of human genetic variation found in modern human populations; where there are more colors of dots on the map, there is more genetic variation. The map shows clearly that most genetic variation is found in Africa, and there is less variation the farther a population is from the African continent.
According to current research, the African continent is the ancestral home of modern humans. Scientists studying patterns il human genetic variation have observed the greatest amount of human genetic diversity in African populations. Genetic variation outside of Africa-in Europe and Asia-includes some, but not all, of the genetic variation found in Africa, which suggests that between 140,000 and 290,000 years ago, Homo sapiens migrated out of Africa to colonize Europe, Asia and the Americas. This “Out of Africa” theory is supported by studies of mtDNA, the Y chromosomeLong strands of DNA found inside the cell nucleus. Human cells each contain 23 pairs..., portions of the X chromosome, and some but not all autosomal (non-sex determining) regions, as well as the archaeological record.