The decline in Y Chromosome: Is it worrisome?

In the past, several studies have spoken of a likely situation in which men may cease to exist on the face of the Earth. However, there might be hope in the form of a study that was published in 2022 in the Proceedings of the National Academy of Sciences. It is revealed that the spiny rat, a rodent species from Japan, has evolved a new male-determining gene as its Y chromosome disappeared.

The Y chromosome is one of two sex chromosomes that determine the sex of an individual in most mammals, including human beings. It is passed down from male parents to male offspring. This chromosome contains the SRY gene, which triggers the development of male gonads and turns a fetus into a male, and is responsible for male fertility, too. It has about 100 protein-coding genes compared to the X chromosome's 900.

The study’s author, Australian geneticist Jennifer A Marshall Graves says, “The human Y chromosome is running out of time. In the last 300 million years, it has lost 1393 of its original 1438 genes, and at this rate it will lose the last 45 in a mere 10 million years.” However, according to her 2022 study , things aren’t looking too bleak for men and society won’t turn into the fabled Amazonian world, where women only exist.

The future

“While the loss of genes on the Y chromosome might seem concerning, it’s important to view this change as part of the broader evolutionary journey. As the human genome evolves, it's possible that other chromosomes may eventually take over the role of determining male sex. In fact, some scientists believe that even if the Y chromosome were to disappear entirely, other genetic mechanisms could emerge to ensure the continuation of male offspring,” says Dr Vaishali Sharma, senior Gynecologist, MD (AIIMS), Infertility specialist.

Moreover, there is evidence from other species that life can adapt to such changes. "Some rodent species, for example, have evolved new sex-determining systems and lost their Y chromosomes. These rats have moved genes from the Y chromosome to other chromosomes, enabling them to continue reproducing without the Y chromosome," says Dr. Juhi Patel, Consultant Obstetrics and Gynaecologist at Shalby Hospital.

While it is true that the Y chromosome is diminishing, it doesn't necessarily indicate that men are in danger of extinction. Nature finds a way to adapt; thus, we might see fresh changes in the future regarding the definition of sex.

How to reduce the risk?

On a personal level, maintaining a healthy lifestyle can play a crucial role in supporting genetic health. “A diet rich in antioxidants, along with the avoidance of harmful habits like smoking and excessive alcohol consumption, can help protect DNA and reduce the risk of genetic mutations. These lifestyle choices are beneficial not just for the Y chromosome, but for overall health and well-being,” says Sharma.

As science and technology advance, genetic engineering may offer solutions if the Y chromosome faces critical challenges in the future. “This field holds the potential to intervene in cases where the Y chromosome is at risk of complete loss, ensuring that male development can continue uninterrupted. Though such scenarios are speculative, the possibilities of genetic engineering provide a sense of hope and security for the future of human genetics,” adds Sharma.