Population genetics is one of the tools we can use to reconstruct the prehistory of humans. By looking at the patterns of genetic diversity present in modern humans (and sufficiently well preserved ancient human remains), we can uncover evidence that favors or disfavors
For example, in the 1990s, it was discovered that human genetic diversity, particularly in the paternally inherited Y chromosome and the maternally inherited mitochondrial DNA, was surprisingly small. This led to the ascension of the “Out of Africa” model of human origins, where all modern humans are descended from a population of Anatomically Modern Humans who most likely evolved in East Africa and then expanded around the globe, emerging from Africa as recently as 100k years ago, and replacing the groups that had populated Eurasia for hundreds of thousands of years.
More recently, large-scale genome sequencing, along with sequencing of DNA recovered from ancient remains of human relatives like the Neanderthals, have complicated the picture yet again. It now appears that the replacement of non-African populations by Anatomically Modern Humans involved a certain degree of gene flow. For instance, it seems that modern humans outside of Africa inherited something like 4% of their DNA from the Neanderthals.
In my own work, I have looked at how the patterns of genetic relatedness can shed light on the social structures of ancient humans. For example, how large were ancient human groups? How connected were they by migration? Were there differences in the migration patterns of males and females? Meaningful answers to these questions require the principled integration of genetic data with information from other sources, including ethnographic data on modern hunter gatherers, archaeological records, and linguistic patterns.
Wilkins, J. F. & Thurner, S. 2010 The Jerusalem game: cultural evolution of the golden rule. Advances in Complex Systems 13, 635-641. [DOI: 10.1142/S0219525910002785] (Advs. Complex Syst. 2010 Wilkins)
Wilkins, J. F. & Godfrey-Smith, P. 2010 Comment on “The Domain of the Replicators: Selection, Neutrality, and Cultural Evolution” by Stephen Lansing and Murray J. Cox. Current Anthropology 52, 105-125. [DOI: 10.1086/657643]
Wilkins, J. F. 2006 Unraveling male and female histories from human genetic data. Curr. Opin. Genet. Dev. 16, 611-617. [DOI: 10.1016/j.gde.2006.10.004] (Curr Opin Genet Dev 2006 Wilkins)
Wilkins, J. F. & Marlowe, F. 2006 Sex-biased migration in humans: what should we expect from genetic data? BioEssays 28, 290-300. [DOI: 10.1002/bies.20378] (Bioessays 2006 Wilkins)