A new UC Berkeley-led study suggests the human family tree may be more complicated than previously understood. Researchers report signs of two unknown archaic hominins, often described as “ghost” lineages, hidden within human DNA. The findings add to growing evidence that modern humans did not only mix with Neanderthals and Denisovans.
According to the research, one of these unidentified lineages appears to have contributed genetic material in Africa more than 50,000 years ago. The other is linked to Eurasia and may trace back more than 1.7 million years. Together, those signals point to ancient encounters with human relatives that have not yet been clearly identified in the fossil record.
The study highlights how DNA can reveal parts of human evolution that bones and archaeological remains alone may miss. Even when no confirmed fossils are available for a population, genetic traces can preserve evidence of contact, migration and interbreeding across very long stretches of time.
If confirmed by further work, the results would deepen the picture of human origins by showing that multiple archaic groups shaped the genomes of later populations. Rather than a simple story centered on a few well-known relatives, human evolution increasingly appears to be a network of overlapping lineages spread across Africa and Eurasia.
