Humans Need To Evolve A New Sex Gene As The Y Chromosome Vanishes

It seems the Y chromosome, the crucial marker of male biology, is slowly vanishing from our genetic makeup.

The human Y chromosome is shrinking and on track to disappear entirely down the evolutionary line, potentially signaling our extinction.

But don’t fret – an alternate sex gene may save the day and, indeed, our species, as Sanjana Gajbhiye reported for Earth.com. In humans and other mammals, it is the Y chromosome that determines the sex of the offspring.

Now for some unsettling news: The human Y chromosome is shrinking and on track to disappear entirely down the evolutionary line, potentially signaling our extinction.

However, hope springs from a curious corner—rodent species that lost their Y chromosome but are thriving nonetheless. In this seemingly bleak scenario, two rodent lineages bring us a glimmer of hope.

The mole voles of Eastern Europe and the spiny rats of Japan have both lost their Y chromosome—and are getting along just fine.

A team led by Asato Kuroiwa from Hokkaido University made a breakthrough in understanding how the spiny rats could continue without the Y chromosome.

They found that most of the genes on the Y chromosome had relocated to other chromosomes. The study was published in the journal Proceedings of the National Academy of Sciences (PNAS).

The Y chromosome might appear underwhelming. Compared to the female dual set of X chromosomes, males possess a lone X chromosome and a rather diminutive chromosome dubbed Y.

Yet, despite its size, the Y chromosome packs quite a wallop. It houses the gene that kick-starts male development in the embryo.

This master sex gene, designated SRY, was pinpointed in 1990. It sets off a chain of genetic events leading to the formation of testes in the baby. The embryonic testis produces male hormones, ensuring the development of male characteristics.

The Y chromosome began with nearly 900 active genes, but over 166 million years, it lost most of them, leaving about 55.

This gene loss over the centuries has led scientists to predict that the Y chromosome might vanish entirely in about 11 million years. This has sparked intense scientific debate and numerous claims and counterclaims about the expected lifespan of our Y chromosome.