Two 'Ghost' Ancestors Found in Modern Human DNA, Revealing Complex Interbreeding

On July 30, a publication in Science, spearheaded by Priya Moorjani from the University of California, Berkeley, revealed that modern human DNA carries remnants of two ancient hominin species. The research team, which examined more than 500 genomes, verified the genetic contributions from Neanderthals and Denisovans, while also uncovering DNA from two 'ghost' ancestors. One of these ancestors, likely Homo heidelbergensis, interbred with H. sapiens over 50,000 years ago, contributing approximately 1% to contemporary genomes, probably prior to the last African migration. The second lineage, termed 'super-archaic,' dates back 1.8 million years and was identified in Oceania, indicating interbreeding with Denisovans. These results highlight the intricate nature of human evolution involving migration and genetic mixing.