There are two opposing views about origin of modern man. According...

There are two models about origin of modern man (Homo sapiens sapiens) i.e. (i) Multiregional model : According to this view, Modern humans evolved in many parts of the world from regional descendants of Homo erectus who dispersed from Africa between 1 and 2 million years ago. (ii) Monogenesis model: According to this view only African descendents of Homo erectus gave rise to modern humans. In late 1980s Rebecca Cann and other geneticists supported this view on the basis of DNA of living humans. They compared the mitochondrial DNA (mtDNA) of a multiathenic sample of more than 100 people representing four continents. The greater the difference between the mtDNAs of two peoples, the longer ago that mtDNAs diverged from a common source. By using bioinformatics, they concluded that the divergence of $m t$ DNA of Africans from common source began just 200,000 years ago, much to late to represent the dispersal of Homo erectus. Thus there are greater variation in Asia than in Africa.