A team of researchers found proof that a ghost species of ancient humans existed. The evidence shows this mysterious species might have bred with the human species which lived in Sub-Saharan Africa. Scientists made this discovery while performing an analysis on saliva.
The divergent gene was found in saliva
Researchers came to the conclusion that intercourse between different hominin species was not uncommon. In fact, the evidence found in saliva supports this interbreeding claim. Scientists already knew the ancestors of modern humans from both Europe and Asia often bred with other species of early hominins, such as Denisovans and Neanderthals.
Now, this new genetic study shows the same practice was common among our African ancestors as well. This proved that interbreeding was not only an isolated practice, but was widespread among all early human species.
Researchers managed to look at the evolution of a protein found in saliva. The mucin protein is called MUC7. They were initially interested in the origin and purpose of the protein, and why it was so important to protect the body from bacterial infections.
Interbreeding was a custom, and not an isolated event
Therefore, researchers looked at the gene of MUC7 in over 2,500 genomes. This is how they discovered Sub-Saharan people had a different version of the gene than other genomes. It was so different that it didn’t match with other genomes. Actually, the gene from Neanderthals and Denisovans was much closer to the typical human genomes than the one discovered in Sub-Saharan humans.
This can only indicate one thing. The genetic material of the early humans in the area got mixed with a ghost species, which can either be a Homo erectus subspecies, or a hominin which hasn’t been discovered yet.
After analyzing the rate at which genes mutate over time, researchers could establish when the interbreeding took place. Around 150,000 years ago, early humans mixed with this ghost species. Also, their evolutionary pathways diverged between 1.5 and 2 million years ago.
Image Source: Simple Wikipedia