Scientists have found that the age of the monkey immunodeficiency virus, considered the precursor of the human immunodeficiency virus, is from 32 thousand to 75 thousand years. With a high degree of probability, the virus is even more ancient, which will force scientists to rethink their ideas about HIV, according to the journal Science
Until now, it was believed that monkey immunodeficiency virus is a relatively young virus with an age of no more than a few hundred years. In order to more accurately establish its origin, the authors of the study carried out a genetic analysis of samples of the virus found in different populations of monkeys on the African continent.
“The biology and geography of monkey immunodeficiency virus is such that it is found everywhere from the Atlantic to the Indian Ocean. It takes many millennia for the virus to spread over such a vast area,”said lead author Preston Marx of Tulane University in the US.
Moreover, DNA analysis of monkeys living in isolation from their counterparts on the island of Bioko for 10 thousand years has shown that the evolution of various modifications of this virus has been going on for at least 32-75 thousand years. The absence of other isolated populations of monkeys does not allow scientists to establish the more ancient "roots" of this virus, but the authors of the article suggest that, most likely, the monkey immunodeficiency virus first appeared more than a million years ago.
This discovery poses several questions for modern researchers of the human immunodeficiency virus.
Firstly, the monkey immunodeficiency virus, as well as the immunodeficiency viruses inherent in other animal species, are not pathogenic - animals can be their carriers and not suffer from reduced immunity. This suggests that HIV, if it really appeared quite recently, having transformed from the monkey immunodeficiency virus, still has a thousand-year evolutionary path to go before becoming harmless to humans.
On the other hand, the venerable age of the monkey immunodeficiency virus suggests that the prehistoric ancestors of humans, who lived side by side with these animals for many hundreds of millennia, were exposed to the virus for a long time. Why did HIV cause the AIDS epidemic only in the 20th century, and was not known until the middle of the last century?
“Something happened in the twentieth century that turned this relatively harmless monkey virus into something that has the ability to cause epidemics. We do not know what kind of event it was, but it should have taken place, concluded Marx.
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