Three articles published in the journal “Nature” describe as many genetic studies that aim to reconstruct the genetic history of modern humans’ migrations. The results agree that non-African populations show traces of a single expansion started from Africa about 75,000 years ago. However, one study suggests that at least 2% of the DNA of the inhabitants of today’s Papua New Guinea comes from a previous migration. One of the studies shows that Aboriginal Australians split from the Papuans about 37,000 years ago.