Researchers discover two unknown ancestral lineages in human DNA

Researchers have identified evidence of two previously unknown ancestral lineages in the DNA of modern humans. Using a new method to analyze the genomes of living people, scientists were able to reconstruct missing parts of the human family tree by working backward from existing DNA.

One of these identified lineages appears to have interbred directly with Homo sapiens in Africa more than 50,000 years ago. The second lineage is an even older group that passed its DNA to humans indirectly through Denisovans. Unlike Neanderthals or Denisovans, whose DNA was recovered from prehistoric remains, these lineages were previously considered 'genetic ghosts' because no direct physical DNA evidence existed for comparison.

The findings, which utilize a method to reconstruct genealogies and map how DNA segments are passed through generations, were published in the journal Science.