Mon. Feb 17th, 2020

They discover an unknown species in the origin of Humanity in Africa



The ancestors of the Africans mated with an archaic or “ghost” species between 360,000 and a million years old and separated from the human family tree even before the Neanderthals

According a study published in “Science Advances” by a group led by scientists from the University of California, states that in the same way that modern humans (Homo sapiens) crossed with Neanderthals in Europe and with Denisovans in Asia and Oceania, the ancestors of Africans mated with an archaic species or that left its mark on the genome of today’s Africans. This spice hitherto crossed 43,000 years ago with African Homo sapiens and left its genetic mark, but since there are no fossil records to prove it, researchers refer to them as the “ghost” species.

The work analyzes the ‘introgression’, that is, the introduction of genes from one species into the genome of another, “and that happens when there is hybridization or crossing between two organisms of the same species or of different species,” Antonio explains to EFE Rosas, Spanish paleontologist of the National Museum of Natural Sciences (MNCN-CSIC). Fortunately, there is a way to get an idea of ​​how ancient humans mixed up that don’t involve studying remains: modern genomics. For this study, Arun Durvasula and Sriram Sankararaman analyzed the genome of 405 living West Africans and compared it to the genomes of Neanderthals and Denisovans.

“By comparing these genomes with a theoretical model, they see their variability and discover that this genetic variation fits with the introgression of genes from different species, that is, it shows that there has been hybridization with archaic species because there are genomic fragments that do not correspond to the variability of Homo sapiens ”, explains the Spanish paleontologist. The authors found populations in West Africa derived between 2 and 19 percent of their genetic ancestry of this ancient hominid not yet discovered.

Characteristics of the new species

The researchers suggest that this ghost species is between 360,000 and one million years old and that it separated from the human family tree even before Neanderthals. These extinct relatives of Homo sapiens transmitted genes to the modern African ancestors Yoruba and Mende approximately 24,000 years or more. It could be a kind of Homo erectus or a descendant “but not a strict H. erectus because the dates of differentiation of that archaic phantom lineage is after Homo erectus,” explains Rosas.

This is not the first time that ‘ghosts’ species of unknown extinct ancestors have been found in modern DNA. Researchers who observed Eurasia DNA have previously found traces of at least three ancient hominins not yet discovered in modern human genomes. But this is the first time for modern West African DNA.

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