Using mtDNA to track the timing and dispersal of modern humans out of Africa

Seminal research by Cann et al. in 1987 demonstrated the utility of mtDNA in understanding both the timing and geographic location of the emergence of modern humans. Just over a decade later Quintana-Murci et al (1999) use mtDNA to shed new light on the timing and route of the first dispersal of modern humans out of Africa, a discussion that has largely focused on the fossil and archaeological evidence. However, estimating timing and route of a dispersal out of Africa is difficult as the fossil and archaeological record in the areas imediately outside of Africa is sparse at best.  By calculating the coalescence time for haplogroup M mtDNA in east Africa and India, they were able to estimate that the first major dispersal of modern humans outside of Africa occured around 60,000 years ago by way of East Africa. This estimate puts the archaeological evidence surrounding modern human dispersals into some context. Based on their findings they also suggest that 100,000 year old skeletal and archaeological remains from Middle Eastern sites Skhul and Qafzeh represent a temporary sortie outside of Africa.