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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.
... 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.
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!
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?
That divergence might occur upstairs between the ears. Some groupings of autistic traits seem to be early precursors of that divergence. Call it a disability if you must, but there's gold in them genes for some folks who get the right combination.
Yes ... those genes DO in fact make your ass look big.
And all that cake isn't helping either ...
Perhaps like Fox News' Ann Coulter suggested that "jews should be perfected".
`echo $[0x853204FA81]|tr 0-9 ionbsdeaml`@gmail.com
Not on a planet of only women, but the topic of having a high percentage of women on the same cycle (i.e. ALL of them) was addressed in this series by Robert J. Sawyer.
Ahh - My eye!
The doctor said I'm not supposed to get Slashdot in it!
Autism is not the superpower that many people make it out to be. You only see the high functioning autistic people. There are a great many who cannot even communicate above an infantile level. Many also suffer from severe OCD. These people need constant care throughout their lives. The brilliance aspect is only found in a small percentage of autistic people, and I've never seen a conclusive study showing that brilliance is any more common among the autistic than it is among "normal" people. It may be that it is simply more noticeable when someone who's autistic has some great talent.
surely the Y chromosome going away would mean the X one following less than 120 year later...??
This seemed like a reasonable sig at the time.
I think that is exactly why he stated "who get the right combination."
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.
I think that the scientists understand that the disappearence of the Y chromosome does not mean the disappearence of men. The reporters, on the other hand...
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
...the Y chromosome is already rotten.
make imaginary.friends COUNT=100 VISIBLE=false
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."
I already responded to the AC w.r.t. your qualification, but I want to add this, since it sounds like you may have taken offense at my post, which was never my intent. I am making no presumptions about you. I am not trying to say that you are bad for thinking the way you do, or anything like that. It's just that after having a lot of first hand experience with actual autistic people, and contrasting that with the way people treat the condition in popular culture (particular the self-diagnosing geeks who seem to want to be autistic), it makes me concerned that people are trivializing what is actually a very serious condition.
I'm not saying that you're trivializing it, at least not intentionally, but when you say things like "call it a disability if you must", it feeds into this common perception that autism is actually a beneficial condition that just comes with the cost of a bit of social awkwardness.
I have yet to see any version of autism that confers any reproductive advantage. All of them I have met have been at a moderate to severe reproductive disadvantage.
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.
My cousin's high functioning autistic. He communicates through quoting 10 minute chunks of dialogue of Family Guy, randomly refuses to leave the house for weeks with violent tantrums and thinks buying 5 gameboys at once and keeping 14 hampsters in his room is normal. Other than that, he's a normal young man. I've got to say though it hasn't destroyed him, it's hardly been beneficial.
When Argumentum ad Hominem falls short, try Argumentum ad Matrem
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?
...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
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Nope, that means you have a good memory.
I can recite family guy too as well as other "cult" or "geek" cannon, but since I am not autistic, I generally choose other ways to communicate than rattling off large amounts of quoted dialogue towards bewildered others.
Our great uncle can multiply two four digit numbers in his head, he never learned how to do it, he just can. But he is certainly not autistic either, he is a normal guy with many friends, a lovely wife and family and had a good career as the Chief Engineer of a large electronics company during the 80s, which would be a rare achievement for even a high functioning autistic.
When Argumentum ad Hominem falls short, try Argumentum ad Matrem
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.
You just communicated WITHOUT quoting something else you've heard.
See the difference?
My son is autistic, and like the above, his conversational skills are limited. In my son's case, he's lucky, as long as he has heard a similar conversation in the past, he can respond. It's almost like a choose-your-story book, based on where the conversation is currently, and everything he's heard before, he can pick a response that seems to fit and say it.
Since he likes sit-coms, he's known in high school as quite the comedian, despite never having said an original joke.
Again, this is high-functioning autistic.
For low-functioning, think of somebody who never speaks actual words and screams when the air conditioner comes on due to the noise. Which would be son's mother's aunt's son ... some forms of autism are due to faulty X-chromosome, so while the symptoms manifest more often in men, the carriers are typically women (since most autistic men won't reproduce).
"Flame away, I wear asbestos underwear"