The Narrative of Human Origins Is Changing: Traces of 'Ghost' Ancestors Found in DNA

The research on human origins has taken a surprising turn. A collaborative study by researchers from the University of California, Berkeley, and Johns Hopkins University has shed new light on the origins of certain DNA sequences in the modern human genome that have remained unexplained for approximately 20 years. The researchers found that these sequences do not belong to the previously studied Neanderthals or Denisovans. According to the research announcement published by UC Berkeley, the team used a new method called 'TRACE' to analyze the genomes of present-day humans. This method aims to identify the traces of past gene transfer to modern humans by examining the relationships between DNA fragments within the genome and their common ancestors. The study suggests that one of these groups may have interbred with our ancestors before Homo sapiens migrated out of Africa. The second genetic contribution is thought to be related to Homo erectus, which migrated from Africa to much of Asia around 2 million years ago. The researchers propose that Homo erectus may have interbred with Denisovans, and these genes were then transferred to modern humans through the Denisovans.