Enamel proteins from six Homo erectus specimens across China

Homo erectus remains have been found in Africa, Eurasia and Southeast Asia1–3, dating back around two million years; however, owing to their age and state of preservation, obtaining informative molecular data from them has proved challenging. Here we successfully extracted and analysed ancient enamel proteins from five male and one female Middle Pleistocene H. erectus specimens from approximately 0.4 million years ago, from the Zhoukoudian, Hexian and Sunjiadong sites. All specimens from all three sites share two amino acid variants. Of these, A253G in AMBN is previously unknown and has not been identified in other human lineages, including H. erectus from Dmanisi (Georgia), Homo antecessor from Atapuerca (Spain), Denisovans, Neanderthals and modern humans. The other variant, AMBN(M273V), has previously been identified in Denisovans, and our evidence now indicates it may have been introduced through populations related to these Middle Pleistocene H. erectus. The regions in the Denisovan genome attributed to super-archaic introgression, some of which later passed to modern humans, are likely to have originated from H. erectus. Late Middle Pleistocene H. erectus may have coexisted with Denisovans in parts of East Asia, where these interactions are presumed to have occurred. Palaeoproteomic analysis of ancient enamel proteins extracted from Middle Pleistocene Homo erectus specimens from the Zhoukoudian, Hexian and Sunjiadong sites in China suggests that they are a new genetic monogroup, and super-archaic introgression in Denisovans is likely to have originated from H. erectus.