The Y chromosome may be “dying”, and this leads to a discussion about whether men are likely to disappear with it.
A person’s sex is determined by whether they have two XX or XY chromosomes. Because the Y chromosome is responsible for the development of male characteristics. In addition, the Y chromosome usually carries the gene responsible for sperm production. Of these two types of chromosome, the X chromosome has about 1,000 genes while the Y chromosome has only 45 genes, and new research shows that the Y chromosome is slowly decreasing in number.
However, over time, the Y chromosome degrades gradually because it has less communication with the X chromosome. Usually, even in the fetus, all other chromosomes in our genome exchange their fragments with homologous chromosomes and this exchange prevent degeneration. This process breaks down genes and makes it more likely that only strong, harmless genes can be passed on.
However, only the X chromosomes are interchangeable, while the Y chromosomes are not homologous enough to combine. For the same reason, none of us carry two YY chromosomes, so the Y chromosome cannot recombine itself, so the number of the mental chromosome has been decreasing over the course of millions of years. evolution of mammals.
Research done by Jennifer Graves, a geneticist at La Trobe University in Melbourne, showed that 166 million years ago, the Y chromosome had the same number of genes as the X chromosome, about 1,669.
“So it doesn’t take a transcendent brain to realize that if the loss rate is the same of the Y chromosome and we have only 45 genes left, then the entire Y chromosome will be. disappeared after 4.5 million years, “said Jennifer Graves.
Research shows that the rate of degradation has slowed over time, and that the human Y chromosome has lost only one gene since humans and other primates split off each other on plants evolving, about 25 million years ago.
But a complete loss of the Y chromosome is still possible, as it has happened to other species including underground rodents such as moles, as well as some species of thorns in Japan. However, this does not mean that the male sex will disappear because of the loss of the Y chromosome.
Rasmus Nielsen, a geneticist at the University of California, Berkeley, said: “People think that sex is a very decisive thing by the chromosome. If you have the Y chromosome, then you are a man, you are. without the Y chromosome, you’re female. But in reality, it doesn’t work that way. ”
In fact, 95% of genes in the body will express the difference between men and women, which is not really entirely based on the X and Y chromosomes. Nielsen explains: “Y chromosome loss is not there. That means losing the male. If the Y chromosome disappears, another gene may play a role in determining main sex in human development.