Ancient Teeth Suggest Interbreeding Between Homo Erectus and Denisovans

New research published in the journal Nature suggests that Homo erectus and Denisovans may have interbred, adding complexity to the human family tree. A team of paleogeneticists from the Chinese Academy of Sciences analyzed proteins extracted from 400,000-year-old Homo erectus teeth discovered at three sites in China. By sequencing peptide chains from the enamel protein ameloblastin, researchers identified two distinct amino acid variants. One variant appears unique to Homo erectus, while the second, known as M273V, was also found in Denisovans. This shared genetic marker indicates potential interbreeding between the two hominin groups. Furthermore, the M273V variant has been detected in a small subset of modern humans in the Philippines, suggesting that Homo erectus DNA may have been passed to modern humans via Denisovans. This finding raises the possibility that Homo erectus could be the mysterious 'ghost' hominin group previously identified in genetic studies. However, due to the age of Homo erectus bones, usable DNA remains unavailable, leaving some aspects of this evolutionary history reliant on protein analysis and speculation.