According to foreign media reports, scientists found that about 200,000 years ago in sub-Saharan Africa, a “ghost-like” ancient human family may have been with the modern (3)…. The ancestral hybrid of human reproduction.
This new study suggests that a protein associated with salivary mucus shows that the ancestors of modern humans have mated with an extinct human branch. And this one of our human relations from the Neanderthal people far away.
The ancestors of modern humans lived together with the Neanderthals and the Daniso people on earth, in which the Neanderthals were the closest relatives of modern humans. Dennysuo people are wandering in Siberia to Southeast Asia. In previous studies, the DNA extracted from the fossils of the Neanderthals and the Danissovs showed that the ancestors of modern humans had mated with these two humans.
Previous studies have also pointed out that modern human ancestors may also mate with other human branches. For example, a 2011 study analyzed modern DNA and found that human ancestors had mated with an extinct human branch before leaving Africa. Researchers have recently found that a protein called mucin-7 in modern saliva in sub-Saharan Africa today may be associated with a “ghostly” ancient human branch.
<about 5% to 7% of residents in this area contain variants of this protein in the saliva of the residents. "The co-author of the study, the evolutionary geneticist of the University of Buffalo, New York, Man (Omer Gokcumen) pointed out. Scientists have studied the effect of mucin-7 protein on human health.
The results show that this molecule can make the saliva become sticky, easy to combine with the micro-organisms, so as to avoid harmful bacteria into the body.
The gene corresponding to the protein is named MUC7. Researchers analyzed 2500 MUC7 genes in the modern human genome and found that the MUC7 gene in the genome of many sub-Saharan Africa was very different from others. In fact, the MUC7 gene in the Neanderthals and Dennysola humans is closer to most people’s genes compared to these special populations.
Researchers believe that these human MUC7 genes may come from a “ghost” human branch. In other words, scientists have not yet found this human fossil. “We did not expect to find such a result, which made us confused.” Gokuman said.
This phenomenon is widespread in Africans, suggesting that the gene may be in the human ancestors before leaving Africa into the modern human genome. Taking into account the rate of genetic variation, the researchers believe that human ancestors and this human mating may occur in 200,000 years ago, and this human branch from the modern human ancestors separated from the time may be 500,000 or 100 million years ago The
“We know that the MUC7 gene has two major functions,” explains Stefan Ruhl, an oral biologist at the University of Buffalo. “One is to lubricate the mouth and help chew and swallow; The second role is more important. “
Scientists from the 130 subjects who collected the mouth, skin, feces and other biological samples, but also to keep the harmful microorganisms in the body, The results showed that different MUC7 genes correspond to different oral flora. “This suggests that the MUC7 gene is associated with oral flora and has a certain effect on viruses, bacteria, parasites or fungi,” says Ruhr. “At the same time, we did not rule out the effect of the gene on lubricating the oral cavity. And when the air is too dry, it will work. “
Next, scientists will further explore the time and place where human ancestors mate with this ancient human race.” Also determine whether this behavior is only Took place once. “Gokman pointed out. Scientists have found that a “ghostly” ancient human family may have breeded with the ancestors of modern humans in sub-Saharan Africa about 200,000 years ago.