A new study suggests that the human Y chromosome, passed down through the paternal line to men, is literally degenerating and may disappear completely in a few million years, writes Science Alert. Such a development would lead to the extinction of humanity, but researchers believe there is still hope if a new sex gene emerges. Fortunately, science already knows such precedents – two clones of rodents that lost their Y chromosome managed to adapt and survive, which means that there is hope for humanity as well.
The X chromosome is known to contain about 900 different genes that perform all sorts of non-sex-related functions. At the same time, the Y chromosome contains just over 50 genes and very simple, repetitive DNA, but also one extremely important gene that triggers male development in the embryo.
About 12 weeks after conception, this key gene, identified by scientists as early as 1990 as SRY, “switches on” and others that control the development of the testicles, producing male hormones, thereby ensuring that the fetus develops as a boy. In earlier studies, scientists concluded that the human Y chromosome would inevitably die. But they continue to argue about the time frame of this event – some are confident that it will not happen at all, while others believe that the process will take not millions, but thousands of years. Humanity needs men and sperm to reproduce, which is why the end of the Y chromosome is causing serious debate about our future.
The new discovery of the survival of the two rodent lineages, in which most of the genes on the Y chromosome are likely to have been transferred to other chromosomes, also gives hope to our species – it can be assumed that humans will be able to develop a new sex-determining gene in the future .
However, scientists suggest that even the development of a new sex gene carries some threat – in different parts of the world it may develop in a different way, and in the distant future we will be threatened by something like a “war of sex genes”. That is, after 11 million years, several different human species may live on Earth, differing in sex determination systems.
Photo by Jill Burrow: https://www.pexels.com/photo/flower-petals-arrangement-forming-a-letter-7400336/
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