Scientists have discovered remnants of ancient ancestors, referred to as ‘ghost ancestors,’ within the human DNA, shedding light on the origins of our genetic composition.
A recent study revealed genetic material from two unidentified groups of hominins, the primate category encompassing humans and Neanderthals. One lineage emerged in Africa approximately 50,000 years ago, while the other, termed ‘super archaic,’ dates back 1.8 million years.
These ‘ghost ancestors’ are believed to have interbred with Denisovans, another extinct hominin group like Neanderthals. This genetic mingling occurred in Eurasia, with Denisovans transmitting the ‘super-archaic’ DNA to Homo sapiens in later millennia.
It is estimated that modern humans carry a comparable amount of ‘ghost DNA’ to that of Neanderthals, accounting for about 1 percent of their genome.
Yulin Zhang, a researcher from UC Berkeley involved in the breakthrough, disclosed, “Approximately 2 percent of the modern human genome originates from archaic hominins.” The study also found that both modern Africans and non-Africans inherited similar proportions of ghost ancestry, constituting around 0.5 to 1 percent of their genetic makeup.
Arjun Biddanda, a co-first author of the research from Johns Hopkins University, expressed excitement about the super-archaic discovery, emphasizing the genetic contributions from a human lineage existing over a million years ago.
Contrary to previous beliefs that ‘ghost DNA’ was exclusive to modern-day Africans, the research indicates an equal distribution among Africans and non-Africans. This suggests extensive interbreeding before Homo sapiens expanded beyond Africa.
The study’s outcomes reinforce the notion that present-day Homo sapiens possess a blend of genes from extinct hominin groups, indicating prolonged interbreeding across different populations to shape the diversity observed in humans today.
