1. Lewin, R. Africa: cradle of modern humans. Science 237, 1292–1295 (1987).
2. Stringer, C.B., Grün, R., Schwarcz, H.P. & Goldberg, P. ESR dates for the hominid burial site of Skhul in Israel. Nature 338, 756–758 (1989).
3. Cavalli-Sforza, L.L., Menozzi, P. & Piazza, A. The History and Geography of Human Genes (Princeton University Press, Princeton,1994).
4. Torroni, A. et al. Asian affinities and continental radiation of the four founding Native American mtDNAs. Am. J. Hum. Genet. 53, 563–590 (1993).
5. Chen, Y.S., Torroni, A., Excoffier, L., Santachiara-Benerecetti, A.S. & Wallace, D.C. Analysis of mtDNA variation in African populations reveals the most ancient of all human continent-specific haplogroups. Am. J. Hum. Genet. 57, 133–149 (1995).