Will men stop being born in the world and only girls will be born? Y chromosome is disappearing, scientists are worried
The sex of the foetus growing in a woman’s womb, i.e. whether it will be a boy or a girl, depends on the chromosomes of the parents. Actually, women’s body has two X chromosomes and men’s body has one X and one Y chromosome. When the XX chromosomes of a man and woman meet, the foetus becomes a girl and when the XY chromosomes meet, a boy is born. That is, for a boy to be born, the presence of a Y chromosome is necessary. If the Y chromosome of men is lost, then no boys will be born, only girls will be born and then there will be no humans left. A similar danger has been expressed in a new research, which says that the Y chromosomes are decreasing.
According to the report of Science Alert, research says that the Y chromosome of humans is decreasing and may disappear completely in the future. However, it will take millions of years to end. If humans are unable to develop a new gene as an alternative to Y and the decline of the Y chromosome continues, then life may end on Earth. The hope of developing a new gene has arisen from a research paper published in 2022 in the Proceedings of the National Academy of Sciences. It describes how the spiny rat has developed a new male-determining gene. This points to an alternative possibility, which says that humans can develop a new sex-determining gene. However, this is not very straightforward and its development will also come with many risks. That is, it would be hasty to consider it an option right now.
How does the Y chromosome determine human sex?
Women and men have an X and a Y chromosome. The X has about 900 genes, while the Y has about 55 genes and a lot of non-coding DNA. The Y chromosome packs a punch as it contains a crucial gene that initiates male development in the foetus. After 12 weeks of conception, this master gene switches on the other genes. This makes the foetus produce male hormones that ensure the baby develops as a boy.
Research says that the disparity between the two chromosomes is increasing. In the last 166 million years, the Y chromosome has lost 900-55 active genes. This is a loss of five genes per million years. At this rate, the last 55 genes will be lost in 11 million years. The decline of the Y chromosome has worried scientists.
Life is possible even without the Y chromosome!
Amidst the concern about the decline of the Y chromosome, scientists have been relieved by two such species of mice, which are still alive even after losing the Y chromosome. There are such species in the spiny mice of Eastern Europe and Japan, whose chromosome and SRY have completely disappeared. In such breeds, the X chromosome works for both sexes. However, it is not clear how to determine sex without the gene.
In the research, Kuroiwa’s team says that the disappearance of the human Y chromosome has led to speculations about our future. It is also possible that after 11 million years from today, there will be no humans on Earth. This is because sperm is required for reproduction. That means the presence of men is necessary for this. It is clear that the end of the Y chromosome can mark the beginning of the extinction of the human race.
