07/08/2025
Scientists are concerned about the Y chromosome's potential disappearance due to its ongoing degeneration. The Y chromosome, which determines male s*x in humans, has been shrinking for millions of years.
Unlike other chromosomes, it lacks a partner for recombination during cell division, limiting its ability to repair genetic errors. Over time, this has led to a loss of functional genes, reducing the Y chromosome to about 55 genes compared to the X chromosome's roughly 900.
Research suggests the Y chromosome has lost 97% of its ancestral genes over 300 million years. In some mammals, like spiny rats, the Y chromosome has vanished entirely, with s*x determination shifting to alternative genetic mechanisms.
This raises questions about whether humans could face a similar fate. Estimates vary, but some studies project the Y chromosome could disappear in 4.6 to 11 million years if degeneration continues at the current rate.
However, the process isn't guaranteed. Some scientists argue the Y chromosome may stabilize, as essential genes like SRY, which triggers male development, are preserved.
