Human Ancestry Traced to Two Diverged Populations Mixing 300,000 Years Ago

A new genetic model indicates modern humans descended from two distinct populations that split 1.5 million years ago and reconnected approximately 300,000 years ago. This challenges the long-held view of Homo sapiens originating from a single lineage in Africa. Researchers at the University of Cambridge analyzed modern human DNA using a novel method called "cobraa" [ko-braa], revealing that 80% of the genome of present-day humans comes from Population A, while 20% comes from Population B. Population A experienced a bottleneck shortly after the split, reducing its genetic diversity. Neanderthals and Denisovans later branched off from this group. Population B contributed genes potentially crucial for brain function and neural processing. The study, published in Nature Genetics, used data from the 1000 Genomes Project, which sequences DNA from diverse populations globally. While Homo erectus and Homo heidelbergensis are potential candidates for these ancestral groups, further research is needed to confirm their identities. The findings suggest interbreeding and genetic exchange played a significant role in species evolution.