Is the disappearing Y chromosome phenomenon real?

Social media is buzzing with a new phenomenon in medical science — the disappearing Y chromosome. For the uninitiated, the sex of human and other mammal babies is determined by a male-determining gene on the Y chromosome.

Remember the island of Themyscira where Wonder Woman hails from? Also known as Paradise Island, it is home to female warriors known as the Amazons who exist peacefully in sisterhood. If the decline of the Y chromosome continues and only female offspring are born, will the world turn into the fictional island of Themyscira? Will men really go extinct?

Although the study of genes has received attention in the last 50 years, our understanding of its role, evolution and diversity is still limited. Hence, the ongoing disappearance of the Y chromosome is still a debated subject.

On that note, here is a detailed breakdown of the chatter around the potentially disappearing Y chromosome, what it means for the future of men and humanity, as a whole, and how the internet is reacting to it.

Understanding the phenomenon of the Y chromosome disappearing and if men need to pack their bags already

What is the role of a Y chromosome in a human?

Is the disappearing Y chromosome phenomenon real? - Augustman MY (1)

For those of you who were too busy worrying about your gym routines and the latest video games to follow your biology classes, no need to fret! Here’s a quick refresher.

The Y chromosome, one of two sex chromosomes, is mainly found in males of most species, including humans. It is passed down from fathers to their sons. It also has a higher mutation rate than the other chromosomes. On the other hand, the X chromosome is present in both males and females.

As compared to the X chromosome, the Y chromosome is genetically degenerated and small. It carries 55 genes with only 27 of them being male-specific compared to the X chromosome’s 900.

However, it carries the SRY gene which triggers the development of male characteristics in embryos. It activates another key gene, SOX9, which is crucial for male development.

Hence, the shrinking of the Y chromosome is concerning. Unlike some reptiles that can reproduce asexually, mammals like humans need sperm to reproduce. Without men, the human species, as we know it, will go extinct.

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Is the Y Chromosome disappearing?

Is the disappearing Y chromosome phenomenon real? - Augustman MY (4)

In a 2012 article published in the National Library of Medicine, an official website of the United States government, Professor Darren Griffin wrote about Australian geneticist Jennifer Graves’ findings of the potential disappearing of the Y chromosome.

Graves debated with Research Scientist Jennifer F Hughes at the 18th International Chromosome Conference in Manchester in August 2011. She argued that not only has the Y in other mammals undergone lineage-specific degradation but it has also already disappeared in some rodent lineages. The Y was once genetically identical to its partner. However, the current human sex chromosomes retain only traces of their ancestry.

In 2023, in a peer-reviewed journal of the National Academy of Sciences (NAS), Proceedings of the National Academy of Sciences (PNAS), it was revealed that the Y chromosome is degenerating after it stopped recombining — a process in which the genetic material from the X and Y chromosomes is mixed during the formation of sperm cells.

The degeneration is so rapid that the Y has already lost 97% of its gene content and is less than one-third the size of the X. The maleness-determining SRY (sex-determining region Y) gene and spermatogenesis genes remain on the Y chromosome.

While the studies are concerning, it is still controversial to determine whether the human Y chromosome has reached an endpoint of degradation or will continue to shrink to the point of disappearing in the next 11 million years.

Meanwhile, Hughes argued that the Y chromosome has not disappeared and can outsmart genetic decay. Additionally, at least eight different genes were added and it has not lost any genes since the human and chimpanzee separated 6 million years ago. Many of the genes subsequently expanded in copy number.

So what does this really mean for men?

Is the disappearing Y chromosome phenomenon real? - Augustman MY (5)

A few rodent species may argue against the downfall of the Y chromosome in humans. It was long known that the males in the Amami spiny rat, Tokudaia osimensis, that lives on the Amami-Oshima Island in Japan, have no Y.

The tiny rat compensated for the loss of Y by creating a new sex-determining gene. According to the article, it was created by a tiny change in the regulatory region upstream of a key pathway gene. However, the SRY gene was missing.

The emergence of the new gene gives us hope that fashioning a new sex-determining gene is possible. It can ease the minds of those who worry about the Y chromosome disappearing, possibly leading to the extinction of men from the planet.

However, this could also mean that multiple new sex-determination systems may evolve in different regions in the far future. Could this mean the emergence of a new human species, each with distinct sex chromosomes? Perhaps in the next couple of million years, the human species will be drastically different from what we see right now.

The internet’s hilarious reaction to the Y chromosome drama

The gradual disappearance of the Y chromosome has become a trending topic on social media. What could have been fodder for sci-fi films has become meme material on the internet instead. Many biology sciolists are busy sharing their opinions on the phenomenon and sharing their unsolicited contributions to medical science.

Is the disappearing Y chromosome phenomenon real? - Augustman MY (2024)

Understanding the phenomenon of the Y chromosome disappearing and if men need to pack their bags already

What is the role of a Y chromosome in a human?

Is the Y Chromosome disappearing?

So what does this really mean for men?

The internet’s hilarious reaction to the Y chromosome drama

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