Health
The Future of Humanity at Risk as Y Chromosome Shrinks
Recent studies have confirmed that the Y chromosome, which is essential for determining male sex in humans, is gradually shrinking in size due to genetic decay. This development raises concerns about the potential future disappearance of the Y chromosome and its implications for human reproduction.
The Y chromosome carries the SRY gene, crucial for male characteristics, and initiates the formation of testes as well as the production of male hormones. This process distinguishes males, who possess one X and one Y chromosome, from females, who have two X chromosomes.
Over the last 166 million years, the Y chromosome has lost over 900 genes, shrinking from a larger structure to approximately 55 active genes today. If this trend continues, the Y chromosome could vanish entirely within the next 11 million years, according to some scientists.
Concerns have been raised regarding the implications of a disappearing Y chromosome on human survival. Currently, humans, unlike some reptiles that reproduce asexually, require both sperm and men for reproduction. If the Y chromosome were to undergo extinction, it could threaten the future of humanity.
However, recent research regarding certain rodent species offers a glimmer of hope. Notably, the spiny rat has successfully evolved a new male-determining gene, allowing the species to thrive without the Y chromosome. This discovery suggests that humans might also develop new mechanisms for sex determination in the future.
In the spiny rat, significant gene relocations have occurred, and a small duplication near the SOX9 gene on chromosome 3 has been identified. This duplication seems to compensate for the missing SRY gene, providing an alternative method for determining male sex.
The adaptability observed in these rodent lineages highlights the possibility that evolution might present solutions for humans as well. Scientists are closely monitoring these changes to gain insights into the future of sex determination in humans and the implications for human evolution.
