DNA Reveals Hidden Human Relatives

A groundbreaking new method is shedding light on our evolutionary past by analyzing modern human DNA. Researchers have identified two previously unknown ancestral lineages, effectively 'ghosts' in our genome with no direct fossil evidence. These findings were published on July 30 in the journal Science.

The TRACE computer-based method reconstructs genealogies, revealing branches of our evolutionary tree. One newly discovered lineage likely interbred with Homo sapiens in Africa over 50,000 years ago. A second, much older lineage, termed 'super-archaic,' traces back about 1.8 million years and interbred with Denisovans in Eurasia more than 200,000 years ago.

These discoveries deepen our understanding of human origins and migration. Scientists suggest these ghost lineages might represent ancient hominins like Homo heidelbergensis or Homo erectus, groups for which no DNA has yet been recovered. Further research using TRACE may uncover more hidden ancestral contributions across various species.