Fig 1. Phylogenetic network showing hypothetical evolutionary scenarios relating modern human populations and their closest relatives.

On the left, a slightly simplified version of an admixture graph from a recent publication on human diversity [8]. On the right, an alternative scenario obtained by applying one of the rearrangement moves that we define here (an rNNI), which essentially swaps the order of the two events immediately ancestral to the Denisovans. S.Afr.: Sub-Saharan Africans, W.Eur.: West Eurasians, E.Asi.: Eastern Asians, Aus.: Australasians, Nea.: Neanderthals, Den.: Denisovans.