Y chromosome at risk, but evolution ensures male survival
New Delhi | Desk: The Y chromosome, which determines male sex in humans, is on the verge of extinction, according to scientists. They say that over the past 300 million years, this chromosome has lost 97 percent of its genes and could disappear entirely in the next few million years. But does this mean that the existence of men is threatened? Experts believe this will not be the case, as nature has already found alternatives in other organisms.
Australian biologist Jenny Graves first warned of this danger in 2002. According to her, the ancestors of mammals had identical X and Y chromosomes, each containing about 800 genes. But 200 million years ago, the Y chromosome took on the responsibility of sex determination, after which it diverged from the X chromosome. As a result, the Y chromosome began to continuously lose genes, while the two X chromosomes in females remained strong by pairing with each other. Today, only three percent of the original genes remain in the Y chromosome.
Graves says, "Men will continue to exist even without the Y chromosome. In the next 5 to 6 million years, a new chromosome will take its place, just as has happened in some species of mice."
For example, in mice such as *Ellobius talpinus*, *Ellobius tancrei*, and *Ellobius alaicus*, the Y chromosome has completely disappeared. Instead, other chromosomes have begun to play the role of sex determination. Similarly, in the *Tokudaia osimensis* mouse, a new chromosome has taken the place of the Y chromosome.
Graves claims that the same process may be underway in humans, and perhaps it has already begun in some isolated community. "If the important genes of the Y chromosome are transferred to another chromosome, it will not affect male fertility," she adds.
However, the scientific community is divided on this theory. Experts like British biologist Jenny Hughes trust in the stability of the Y chromosome. In 2012, Hughes demonstrated with data that the Y chromosome has lost very few genes over the past 25 million years.
"The decay was rapid in the early stages, but it has now stopped. The genes on the Y chromosome are extremely important for the human body, so the body won't easily let go of them," says Hughes. Her study showed that the Y chromosome has stabilized in many mammals, and no new gene loss has occurred.
Graves rejects this argument. She argues that new genes are being created on the Y chromosome, but they are mostly inactive-a clear sign of impending extinction.
According to evolutionary biologists, this process is part of natural selection, which adapts organisms to new challenges. Nevertheless, the question remains: will human civilization lose its gender balance?
Experts assure us that nature has always maintained a balance, and the human species will continue to thrive even without the Y chromosome.
This debate touches not only on science but also on the profound aspects of human existence. As research progresses, perhaps we will get a more accurate picture of the Y chromosome's future. Until then, men need not worry; evolution will not abandon them.
