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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."
I tend to shed my genes all over the place ... on the floor, in some Kleenex, in dirty socks...
While our Y chromosome may make us (men) more susceptible to genetic diseases, it also allows for more rapid adaptation and spread if a mutation is beneficial. I certainly wouldn't want it to go away.
It's a common condition afflicting millions of male zombies worldwide.
Even if it had been true that males would "go extinct" from this, I'm not at all convinced humanity will even resemble today's humans in the millions of years it would have taken to occur. In fact, I suspect humanity will diverge radically within the coming tens/hundreds/thousands of years from other countless other factors that we may not have even considered yet.
Write failed: Broken pipe
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
The next natural step is the complete disappearance of the chromosome.
... go-forward time machine. That way, when Sally McKnight in high school told me, "No way, not if you were literally the last man alive", I can finally test this theory!
I'm not getting absolutely no sex because I'm a hideous subhuman monster, physically and emotionally... no. I'm doing it for SCIENCE.
Check out my sci-fi book "Lacuna" at http://goo.gl/MVxX8
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.
I remember some rabid man-hating feminists really trumpeting the theory that in 100,000 to 2 million years y chromosome would disappear. hah!
I expect to be dead long before it happens.
Then again, on the off chance that I am one of the immortals (and I just haven't run into Connor McLeod yet) I'll be happy knowing that I still have my Y chromosomes even if no one else does.
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.
So, genders have been around for hundreds of millions of years - why would anybody think that evolution would suddenly make them go away?
In humans it probably doesn't make so much sense to have lots of sex-linked characteristics, so it makes perfect sense that the contents of the Y chromosome would dwindle over time to just the minimal set of genes necessary to confer gender. After that there should be strong selective pressure to conserve things.
Suppose for the sake of argument somebody is born with a Y' chromosome that doesn't confer maleness. Either they'll have non-functional reproductive organs, or functional female ones. In the former case they're an evolutionary dead-end. In the latter case and they reproduce with an XY man then 25% of their children will be normal XX females, 25% will be Y'Y offspring that won't make it to birth lacking an X chromosome, 25% will be normal XY males, and 25% will be XY' like the mother. So, in 75% of those cases the Y' chromosome is lost. And all that assumes that there aren't any deformities/etc that make reproduction less likely. I can't see how such a situation could ever become dominant. It would likely reach some low frequency equilibrium even if not harmful.
The fact that it hasn't already happened makes me think that it is not likely to do so.
The others that were lost simply weren't necessary to the male role; it was a streamlining process to make us lean and mean procreative machines. It's not like all the males conceived at those earlier times suddenly and simultaneously lost one... it was a gradual overlapping process. It was... EVOLUTION. Go figure!
rotting,.. you mean perfecting?
I guess metrosexuals, hipsters, emo kids, and several other groups were never in any danger in the first place...
Do not look into laser with remaining eye.
Not like I love the Nature Publishing Group (NPG) very much, but let's link to the source to help give the original authors credit. (Which, as far as I can tell, the medical daily article doesn't even do!)
Here is a link to the original paper
For those who aren't molecular biologists or geneticists, here is a link to the Nature news article on the scientific paper
-Ryan
AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
If I search for "rotting y theory", all I get are variations of this article. Why would anyone who knows anything about evolution and genetics actually think that? And who were these people?
Did you just call my genes fat????
It's not "fat"... but you could lose some genes...
[Sexist but inevitable joke]
The genes present at women but not at men are instructions about how to make a sandwich.
Seriously speaking now, even if Y chrom' ceases to exist, male gender goes on. But instead of gender being defined as XX/XY, it would be XX/XØ. Lots of species in the nature work like that: grasshoppers and cockroaches and whatever.
Nerdy news for your nerdy needs? http://www.soylentnews.org Soylent News is people!
Yes ... those genes DO in fact make your ass look big.
And all that cake isn't helping either ...
I don't think a theory suggesting the extinction of males just because the y chromosome is small is sufficiently prevalent to require debunking. If so the state of science is far worse than I had imagined...
XML is like violence. If it doesn't solve the problem, use more.
What do you mean 19 genes - there are only 16.
Where did you get that ridiculous idea?
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Just finished teaching the units on male and female sexual development at a major medical school last week. Even my students know that you need part of the human Y chromosome (SRY gene) to make testes differentiate from primordial gonad tissue. It also makes the 'pre-Fallopian tubes' and what would become uterus and much of vagina (Mullerian duct system) "go away" in developing male fetuses. If SRY gene "jumps" to another chromosome, you don't get proper differentiation of gonads and genitalia. No SRY, general 'female type' morphogenesis. No Y, no sperm, no babies without cloning or parthenogenesis. Without the X and Y autosomes we really lose the basis for most human sexual reproduction... No fun (for standard hetero sex repro) even if you do like sci-fi and scenarios of massive gene and body engineering! Still I seem to recall one or two sci-fi Amazon (non-dot com) societies with parthenogenesis out there in the meta-universe.
The goal is that Space-station orbitting the Earth is full of grey reptilian aliens that want to destroy the women of Earth by mutating the male genes out of existance to leave them either a choice of becoming tribbing Lesbians like birds and honeybee drones or accept the fate of being double-dicked by reptile-men.
I am a beareded lesbian, borne with a modified oviposittor; the grey aliens can't win no matter whom I mutate into.
It wont be long before males are totally unnecessary. Fertilize a female egg with female skin/mouth cells and that will be the end of the y chromosome. Together with some kind of incubator (sure to be developed in the future) and that will be the end of it.
...the Y chromosome is already rotten.
make imaginary.friends COUNT=100 VISIBLE=false
I think that the assumption is that those genes would move elsewhere and other mechanisms would develop to control differentiation. Other lifeforms manage it.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Well, I guess I can stop work on my time machine, they won't be needing me for insemination like I'd hoped.
Have gnu, will travel.
The question being what would be the mechanism to drive such a change. Just because we want to create a pattern doesn't mean we can absent of some scientific explanation as to why that would be the case.
XML is like violence. If it doesn't solve the problem, use more.
Yeah, yeah, I know. There is some internet rule about not correcting people's writing. But this is getting ridiculous! I see common words smashed together more and more often lately. Too often to be mere typos. Come on, people. Read over your posts at least once before clicking submit.
The point of the article seems to be that the change is not ocurring.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Is this related to the fact that mammalian genomes have been shrinking since the extinction of the dinosaurs?
Reducing size is one thing, degenerating down to nothing makes no sense. Sexual reproduction is still going strong after 500 or 600 million years.
I reminded of the "prediction" that Pluto, will all the downward recalculations of its mass since its discovery, would end up with negative mass and negative volume by mid 21st century.
After decoding the 25 million years old rhesus macaque, an ancestor to both chimpanzees and humans researchers found that the macaque Y contained just 20 genes, just one more that the human Y has lost, and although the human Y chromosome has lengthened and grown significantly longer than the macaque chromosome, the genes were mostly the same.
Seriously, WTF?
The Appendix is a vestigial organ. It used to do something useful. That said, it's now kind of pointless, however it won't go away. The problem is that its now as small as it can safely get. Any smaller and it becomes a black hole for anything passing through the gut, and boom! Appendicitis. So there is this powerful Darwinian selection factor for it to be small, but not too small, and certainly not gone.
Of course, if women ever get parthenogenesis nailed down, you guys should get really worried. We women would keep the last couple remaining guys in a petting zoo.
All of us living now are unaffected by this. Why does anyone care if its true or not?
I want to delete my account but Slashdot doesn't allow it.
Screw that. The only reason to have a girlfriend is so she can kill spiders.
Also sex.
But mostly killing spiders.
This story starts out with the claim that biologists predicted the Y chromosome would rot and fall apart somehow and men would disappear. Which biologists, where? This isn't a theory, it's an unfounded hypothesis that scientists do not take seriously. What benefit to survival or reproduction would it serve? If there's no benefit, there's no reason it would happen. If it's a detriment, it would almost certainly not happen, as those with the gene loss would be less likely to survive to reproduce.
Regardless, this was not a theory, was not predicted by "biologists", and was passed along virally, not scientifically.
Back in the day there was a Far Side cartoon of a cave man forming cylinder-like shapes with his hands, holding them to his eyes like binoculars and staring intently at the table in front of him. The caption read: Prehistoric Microbiologists. I always thought: "Stupid caveman! He can't see anything." Now I realize he was staring at a Y chromosome... Because it would have been that much larger in his day.
It would appear, however, that Y chromosomes are a bit more robust than originally thought, and may be able to continue at their present level of basic function for tens of millions of years more. Just as my own thought, one reason for this may be the presence of genes on the Y which are necessary for sperm production. A transition to another form of sex determination would require those genes to be either moved or their functionality replaced elsewhere; otherwise any Y-less males would be azoospermic and therefore the new system wouldn't get passed on.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
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.
The appendix dilemma has already been "solved". If you get diarrhea, the appendix is the place where you keep a cache of intestinal fauna so you can digest food again quickly, once the bad stuff has all been flushed out. If you don't have one, you'll be much more likely to suffer from digestive trouble and healing from diseases will take you longer. Until very recently in the western world, and still in very large parts of the 3rd world, having an appendix is an evolutionary beneficial thing, because you'll die from hunger and disease a lot quicker than everyone else competing for the little food there is.
I was promised a flying car. Where is my flying car?
I dont really have a picture of all female future, but it certainly increases remaining males chances
Go there and you can see males becoming females before your very eyes.
The Internet will eventually cause the developed world to evolve itself out of existence.
...mutate itself out of existence, leading to the eventual extinction of men
That is unscientific hyperbole. The probable long term outcome of genes disappearing from the Y chromosome is that it would only carry the sex determination (SRY) gene, which is just what has already happened in Kangaroos. After that point, further evolution might lead to an entirely new system of sex determination, such as those arising in some species of vole.
Even for rapidly evolving systems such as the SRY gene, Y chromosome and any replacement system, these changes take millions of years. There's no reason to believe that men, or whatever we are calling them then, will suddenly disappear, leaving the species unable to reproduce without technologically induced parthenogenesis.
.: Semper Absurda
You could lose the codong DNA, but not the noncodong, or dong DNA itself.
That is obviously critical to making a male with the requisite dong.
Ba-da-bump
I'll be here all week. Try the primordial soup.
Expect car insurance to go up in the future.
I find it rather suspicious that the search for "rotting Y chromosome" leads only to news about this "Rotting Y chromosome" theory being debunked. Usually it indicates a non issue.
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
I see this especially in the social sciences, and I've heard things like "what is the evolutionary reason for having grandmothers" which may not even have a reason other than mothers not dying or losing maternal instincts.
In that particular case, the question is a legit one. We can see that species with shorter life cycle are more robust and early dismissal of "used up" units leaves more resources in environment to new generations. When we see a specie with long lifespan, it is natural to ask ourselves "Why is prolonged life, beyond unit's fertile age, so good for them that it weights against wasted resources that instead could had been used to support more offspring?" I don't know what the answer was but there aren't many species with grandmothers and in all of them old females are groups' memory (experience) banks.
What will they debunk next. Global Warming .... lets all hope so.
That's a pity, I think there's still at least one there that we could do without
Oh great, now I'm not even going to be a man in the future... If I'm not a man, what on earth will I be?
Just another hole in the evolutionary theory.
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.
That must be a new meaning of the word "biologists" that I wasn't previously aware of. 51% of all humans born are male (which is actually quite inefficient, from a reproductive point of view).