Are Men Going Extinct? Studies Spark Controversy

                                                                    Are Men Going Extinct?                                                                                                                            

Are Men Going Extinct? Studies Spark Controversy

An old question has resurfaced, reigniting debate in scientific and media circles recently: "Is the Y chromosome, responsible for determining male sex, heading towards extinction?"

This chromosome, which holds the secret to maleness in humans, has undergone 97% evolutionary change over 300 million years. This has led some scientists to speculate that its role may end within the next few million years, according to the science website ScienceAlert.

However, evolutionary biologist Jenny Greaves, whose initial calculations caused a global sensation two decades ago, asserted that this does not mean the extinction of men, as some media outlets have suggested, but rather a possible evolutionary scenario. She stated, "It amazes me that anyone would fear the extinction of men in 6 million years, when we as humans cannot even guarantee our survival for the next 100 years!"

Males Without the Y Chromosome

The evolutionary history of organisms has proven that the loss of the Y chromosome does not necessarily mean the end of males. Indeed, it has already happened. 

Several species have this phenomenon without affecting their reproduction, including the Ellobius mole rat, which lives without any copies of the Y chromosome after the sex-determining genes were transferred to other chromosomes. Similarly, Tokudaya rats have replaced the Y chromosome with a new evolutionary version that efficiently performs the function of determining maleness. 

All these examples support the hypothesis that genes adapt and change their positions within the genome without disrupting reproductive function.

Y, X chromosomes (Illustrative image - iStock)

Has the change begun without our knowledge?

In this context, Greaves explained that scientists may not easily detect the transfer of sex-determining function to another gene because genetic studies are not usually designed to look for "alternative sex." She continued, "There may be a population of humans that has developed a new, more efficient gene... and perhaps this has already happened without us noticing."

Two Different Schools of Thought

Amid this ongoing debate, two scientific schools of thought have emerged. The first, represented by Greaves, is the "continuous decay" school, which argues that the Y chromosome continues its slow decline and that its replacement is a matter of... Time. 

One school of thought describes it as a "genetic waste dump" due to the abundance of ineffective duplicates. The second school is the "long-term stability" school, led by MIT. Researcher Jane Hughes explained that the Y chromosome has become stable after a period of rapid loss in the past, losing almost no components in the last 25 million years.

Hughes also asserted that "the remaining genes on the Y chromosome are essential for the entire body, and natural selection will not allow their loss." However, the disagreement between the two schools is not merely a theoretical debate; it reflects two contrasting visions of the concept of evolution itself and raises a timeless question: "Is stability the norm... or is constant change the destiny of genes?"

How did the Y chromosome shrink?

Regarding the scientific background of the debate, research indicates that the Y chromosome was initially a replica of the X chromosome, containing approximately 800 genes. 

However, as it began to function as the sex-determining gene, it lost the ability to exchange genes with the X chromosome, making it susceptible to a gradual loss of information over millions of years... and today, only a small portion remains. Three percent of its original genes.

While this decline sees significant, scientists agree that gene loss hasn't been gradual, making any estimate of its extinction "merely a broad guess." Graves succinctly summarized the situation, but simultaneously left millions perplexed, stating that "the evolutionary history of the Y chromosome could lead to its demise... or it could lead to its stabilization. The possibilities are open now and forever."

Ultimately, everyone agrees that the future of men isn't in danger, but the future of the Y chromosome could change. Even if the Y chromosome were to disappear one day, a replacement gene would emerge to take over—as has happened repeatedly in nature. According to numerous studies, masculinity isn't determined by a single chromosome, but rather by an evolutionary process in which genes can be remarkably rearranged.