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Biologists Debunk the "Rotting Y Chromosome" Theory
An anonymous reader writes "Biologists have previously predicted that that the male sex-determining Y chromosome, which once carried around 800 genes, like the X, has lost hundreds of them over the past 300 million years, will mutate itself out of existence, leading to the eventual extinction of men. However, researchers of a study published in the latest issue of Nature found evidence to suggest that the Y chromosome will not shed any more of the 19 ancestral genes that it is left with."
It really seems like a non-issue regardless of whether or not the Y chromosome is "rotting." Evolution moves slowly enough that by the time it would become an issue, humans will probably have learned enough about genetics to prevent it from happening if necessary. The other alternative is that we decide it's a good idea and speed the process up by a lot.
But the Y chromosome evolved because sexual reproduction has advantages over asexual reproduction. Until that is nolonger true I can't imagine Y going anywhere.
Suppose that someone inherited from his father an Y-Chromosome without the "Manliness Gene". Then he would not have a functioning reproductive system and leave no offspring. The "Manliness Gene" can be lost by a random mutation, but the mutation will never be carried on to the following generation, unless a new sex-determining mechanism already exists.
In soviet russia the government regulates the companies.
If "the right combination" is intelligence + virtually no trace of autism symptoms, then why not just take the intelligence part and leave off the crippling disability? Autism is not a prerequisite to high intelligence. There are plenty of truly brilliant people out there who aren't autistic at all.
I used to work in a school for autistic children. I was just the IT guy, but I was in the classroom at times and saw how hard the kids had to work to grasp things that most toddlers can do intuitively. I think it's unfortunate that when kids like that overcome their illness and do great things, people think "Wow, he sure benefited from those genes" instead of "Wow, that guy must have worked really hard to become so brilliant despite his disability."
Bingo!
Humans would have to evolve a new mechanism of determining sex before the Y chromosome could lose its function.
It's always been obvious that the disappearing Y was bullshit. What we have is a selection pressure that shrinks the Y down to its essential core, which apparently is not much less than the 19 genes and other noncodong DNA it carries in humans.
What is so worrying about a chromosome becoming smaller over millions of years? If any of the genes that were on it were vital to humans, we wouldn't be here (or rather, they wouldn't have disappeared, since their absence would have been selected against). And what's with the extrapolation - can you really take a past evolutionary trend and use it to project future changes?
If that worries you, how about this: Within a much smaller time frame, our fur has disappeared, our bones and skin have become thinner and our brains have grown. If that trend continues, then eventually we'll have no bones or skin, and our brains will be too big for our bodies to carry.