Y Chromosome Is on the Verge of Extinction: What Does This Mean for Future Men?
The human Y chromosome, crucial for male development in the embryo, has been steadily losing genes for millions of years. Currently, only 45 genes remain out of the original 1,438, and scientists estimate that it could disappear completely within 11 million years. This genetic decline has raised concerns about the future of human reproduction, particularly the survival of male offspring. However, recent research offers a glimmer of hope that males can continue to exist even if the Y chromosome disappears.
What is the Y chromosome?
The Y chromosome is one of two sex chromosomes in humans, the other being the X chromosome. It carries genes essential for the development of male reproductive organs, such as the testicles, and plays a crucial role in determining male sex. Males typically have one X and one Y chromosome (XY), while females have two X chromosomes (XX). However, the Y chromosome is significantly smaller than the X chromosome and contains far fewer genes.
The decrease of the Y chromosome
In a study Published in the Proceedings of the National Academy of Science, Professor Jennifer A. Marshall Graves, a leading geneticist and Vice Chancellor’s Fellow, has pointed out that the human Y chromosome is on a trajectory of degeneration. Over the past 300 million years, it has lost 1,393 of its original genes, and at the current rate, it could lose the remaining 45 within the next 10 million years, the author pointed out in the study. This possible extinction of the Y chromosome has led to speculation about the future of human males and the continuity of our species.
Hope of the spiny rat
Despite the bleak outlook, there is reason for optimism. study led by Dr. Asato Kuroiwa of Hokkaido University, discovered that the spiny rat, a species native to Japan, evolved a new mechanism for male development after its Y chromosome disappeared. In this species, genes from the Y chromosome migrated to other chromosomes, and a small DNA duplication near the SOX9 gene on chromosome 3 took over the role of the missing SRY gene, which is responsible for initiating male development.
Survival through evolution
The spiny rat’s adaptation suggests that mammals, including humans, could evolve alternative sex-determination mechanisms if the Y chromosome were to disappear. Another rodent species, the mole vole, has also lost its Y chromosome and survived, further supporting this possibility.
However, scientists warn that such evolutionary changes could lead to the emergence of different sex determination systems in different human populations, potentially resulting in the development of new species.
While the disappearance of the Y chromosome poses a major challenge, this research offers hope that humans can adapt and evolve new genetic pathways to ensure the continuation of male offspring.
