The Y chromosome, the carrier of male identity, is slowly erased. Is this disappearance a sign of the end of the human species? A recent discovery in Japanese spiny mice offers a glimmer of hope. Could a new sex gene ensure human longevity?
Evolution never ceases to amaze us. Whereas the Y chromosome determines the male sex. MammalsMammalsJapanese researchers have highlighted that it is becoming unsustainable. the lightthe light An alternative mechanism of sex determination in some The mouseThe mouse. The discovery was published in February 2024 in the journal Proceedings of the National Academy of Scienceopens new perspectives on the future and evolution of human reproduction. SpeciesSpecies.
Decline of the Y Chromosome: A Threat to Humanity?
The Y chromosome, which carries the SRY gene responsible for male development, gets shorter over generations. In 166 million years of divergent evolution, it has lost about 850 genes. At this rate, the remaining 55 genes could be lost within 11 million years.
This approach raises important questions about the future of our species:
- How to determine gender without Y chromosome?
- Is it a threat to human reproduction?
- Is the end of man inevitable?
In contrast to ReptilesReptiles capable of parthenogenesisparthenogenesismammals require paternal genes to reproduce. Without sperm, and therefore without men, the human species would cease to exist. But nature has more than one trick up its evolutionary sleeve.
Spiny mice: pioneers of a new sex system
Hokkaido University Professor Asato Kuroiwa’s team has made an interesting discovery in Japanese mice. These mice, spread across three Japanese islands, have lost their Y chromosome and the SRY gene, but continue to reproduce.
The researchers identified a small copy of the DNA near the SOX9 gene, which is only found in males. This sequence of 17,000 base pairs out of 3 billion in their genome appears to play an important role in determining sex.
Species |
Chromosome Y |
SRY Jain |
A new mechanism |
Human beings |
Here |
Here |
Absent |
Spiny mice. |
Absent |
Absent |
Transcription near SOX9 |
This finding suggests that human evolution may have produced substitutions for the Y chromosome to determine sex. Hope for the future of humanity?
Evolution in Action: Adaptation or Speculation?
Appearance of a new sex gene in vertebrate mice reveals potential for species adaptation. But, this process is not without risk. L’appearanceappearance may lead to different sex-determination systems SeparationSeparation new species.
Let’s imagine for a moment humanity’s future in 11 million years:
- Complete extinction due to lack of sex-determining mechanism;
- survival thanks to the evolution of a new sex gene;
- The emergence of several different human species, each with its own sex-determination system.
This last hypothesis, although speculative, is reminiscent of the evolutionary history of A wise manA wise man, Homo neanderthalensis And other human species are now extinct.
Toward a New Concept of Sexual Identity
Beyond the biological implications, this research invites us to rethink our conceptualization of gender identity. If the Y chromosome is no longer the sole determinant of male sex, how can we define masculinity?
This question, long confined to the field of biology, may soon find its way into social debates on gender and identity. Evolution continues to remind us that nature is far more complex and fascinating than our categories sometimes suggest.
The future of humanity may no longer depend on chromosomes, but on our ability to adapt and evolve, both biologically and conceptually.