The age of Men is over. The time of the Orc has come.
Yeah you forgot the reason why, which doesn’t make any sense 💀💀💀
In platypus, the XY pair is just an ordinary chromosome, with two equal members. This suggests the mammal X and Y were an ordinary pair of chromosomes not that long ago.
In turn, this must mean the Y chromosome has lost 900–55 active genes over the 166 million years that humans and platypus have been evolving separately. That’s a loss of about five genes per million years. At this rate, the last 55 genes will be gone in 11 million years.
What kind of logic is that what the hell
Yeah, there are examples of the male chromosome being eliminated (some types of stick insects) but it’s way more complex than that. Not only are chromosome degradation processes pretty fast in evolutionary time, highly conserved genes tend to be pretty resistant, sometimes even jumping chromosome if there’s a degradation event.
“given the average rate of gene loss over geological time, we’re several billion years overdue for ATPase disappearing” is my next pop-sci take.
Also, wouldn’t Y-chromosome shrinkage most likely follow an exponential decay curve?
It depends (there’s a lot more than X and Y in the animal kingdom), but broadly and loosely yes. It tends to be long periods of relative stability punctuated by rapid gene loss/transfer, followed by stabilisation of the smaller chromosome. The suppression of recombination that allows for a strong and stable sex division to develop also kind of makes that chromosome less stable. Y and X were probably, originally, hermaphoditic chromosomes that then had one develop a dominant male allele and then to stabilise it developed the SRY gene to regulate it.
