Scientists estimate that the Y chromosome, which is responsible for determining male gender, should disappear. Clues to the future of the species can be found in mice
02/23/2024 8:37 p.m
(updated on February 24, 2024 at 10:45 a.m.)
The Y chromosome, carrier of a gene that determines the appearance of male sex, is “disappearing” in the human species. However, its complete extinction will not occur for 11 million years, a period long enough for a new gene that determines sex to evolve. In short, this will not be the end of man and the species will be selfperpetuating.
Photo: frender/envato / Canaltech
To reassure people in distress: Two (known) species of rats have already lost their Y chromosome in the wild, but have survived and provide valuable clues about the future of humanity.
What is a Y chromosome?
In most mammals, including humans, females have two X chromosomes, while males have a single X chromosome and a small chromosome called Y yes, it's smaller than the others.
OX contains about 900 genes, most of which play roles unrelated to biological sex. In the case of Y, there are about 55 genes and a lot of genetic material with no known use.
Experts reveal that the Y chromosome should disappear in a few million years (Image: Davien Donald/Pixabay)
Photo: Canaltech
As for gender, the Y chromosome contains the “master” sex gene SRY. During the first few weeks of pregnancy, SRY is activated and begins development of the testicles in the embryos, enabling future production of hormones such as testosterone.
Why does the Y chromosome “disappear”?
What causes the disappearance of the Y is still a mystery to science, but this chromosome already has fewer genes than, for example, the X. On average, five new genes are lost every million years. In 11 million years it will be completely gone.
What will happen to the people?
Quiet! Jenny Graves, a professor of genetics at La Trobe University in Australia, explains that at the end of this period the human species should not evolve to include only women.
“Some lizards and snakes are exclusively female species and can produce eggs from their own genes through a process called parthenogenesis. However, this cannot happen in humans or other mammals,” says Graves in an article for The Conversation.
Learn from rodents
For the expert, the future of the human species is closer to what has already happened with some wild rodents, such as Microtus rossiaemeridionalis from Eastern Europe and Tokudaia muenninki from Japan. Both continue to reproduce, even without the Y chromosome.
In the case of the Japanese rat, a recent study published in the Proceedings of the National Academy of Science (PNAS) details the changes between genes and how new males are created during pregnancy.
Next, get to know this type of rat:
 
Led by Japanese researchers, including members of the Tokyo Institute of Technology, the study shows that most of the genes present on the Y have been relocated to other chromosomes and new ones have also emerged. Thus, males continue to be born, but in new ways that involve a different sexdetermining gene.
Source: PNAS and The Conversation
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