Posted on 01/24/2010 7:05:10 AM PST by TigerLikesRooster
Why the Y chromosome is a hotbed for evolution
Mark Henderson, Science Editor
The Y chromosome is often seen as the rotten corner of the human genome — a place of evolutionary decline that is slowly decaying and threatening the end of man. Reports of its imminent demise, however, have been exaggerated.
Research has indicated that, far from stagnating, the male chromosome is a hotspot of evolution that is changing more quickly than any other part of humanity’s genetic code.
In most mammals the sex of offspring is determined by X and Y chromosomes. Females have two Xs, males have one X and one Y — with the Y making them male. The Y was originally identical to the X, but over 300 million years it has shrunk, and is now the smallest human chromosome.
This is because it occurs on its own, and cannot swap genes to maintain integrity. This decline has led scientists to suggest it would waste away entirely in 125,000 years or so. This would mean the end of men, and probably of humanity.
But the first comparison of the human Y chromosome with its counterpart in chimpanzees has revealed that they differ radically. The findings suggest that the Y chromosomes of both are evolving rapidly and dynamically — probably because of their critical roles in reproduction — and have a vibrant future.
(Excerpt) Read more at timesonline.co.uk ...
*Insert Snarky Comment About Ape-ish Ex-Husband Here*
People are so dense ... predetermined outcome based science isn't working.
Oh Boy,
That Was Close!
Almost Evolved out of Existance! LoL !
How ‘Bout a Big Bang,?
That Would Be Nice !
What A Total Bunch Of Wackos These ‘EVOS’ are.
Oh yeah? Then why did I have a banana with breakfast this morning?
LOL!
This is a lie. There are regions of Y that get swapped with X during meiosis, and Y has to maintain analogous sections with X in order to in order for them to go separate ways during division and only have one per sperm.
God is an EVO.
George: Elaine! Do women know about shrinkage?
Elaine: You mean like laundry?
Jerry: Like when a man goes swimming... afterwards...
Elaine: It shrinks?!
Jerry: Like a frightened turtle.
Elaine: Why does it shrink?
George: It just does.
Elaine: I don’t know how you guys walk around with those things.
Did you bite into it with your incisors or canines?
The author failed biology.
“most mammals” ???????? Name one mammal that doesn’t have males with a “Y”
But , Who Gets The KIDS?
OK, And those Funny Red Hats?
That was DEVO.
What a ridiculous statement. This mechanism for reproduction has been around for hundreds of millions of years, maybe longer--there is no scientific basis whatsoever for hypothesizing that it's on the verge of disappearing. There is very strong selective pressure for maintaining a functional Y chromosome.
Mark Henderson may be the scientific editor for the Times, but he is no biologist.
He would have been correct to say "many vertebrates." In birds, for example, the female carries the Y chromosome.
Incisors, but I had my canines on standby in case it tried to get away ;0)
And I thought size counts.
Loks we will all be metrosexuals in years to come.
[Mr] T
Yeah, right. What a dumb ass. I teach my five kids about evolution, but it really isn't necessary. They can just look at a monkey and realize we are related. And guess what?! We are Christians too.
just looked down from heaven and smiled.
There goes the whole core of feminist ideology.
Are you claiming that apes simply forgot to jump onboard the evolution train?
Otherwise, why do they remain un-evolved apes with no prospects of turning into humans?
Obviously you've never been to a Chandler family reunion.
Perhaps his Y chromosome mutated in the wrong direction causing an inability to keep his jeans (genes) up.
:-)
If you’re being serious, then I think you have deep misunderstanding of evolutionary theory. Any good basic book on the topic would serve better than trying to answer your questions without a framework.
Your premise is faulty, in almost exactly the same way as the following would be:
Why do there remain car insurance providers with no prospect of turning into life insurance providers?
A biological environment provides many potential ways of making a living, just as an economy provides many ways of making a living. The goal of evolution is not becoming one particular kind of a creature, but rather simply finding a good way to make a living. (Actually the goal of evolution is to successfully raise offspring, but a creature has to first make a living to do that.)
You make a living dong your thing as a biological organisms in an environment where other organisms are following variously differing approaches, just as you make a living in an economy by following your profession, while other players follow different professions. An ecology consisting entirely of humans is as nonsensical and impossible as an economy consisting entirely of insurance salesman.
Even an economy where not all players are actuaries, but where all actuaries only sell life insurance, is nonsensical. Obviously there are lots of ways to make a living as an actuary. It is usual in the evolution of an economy that all those niches will be filled. If everyone is selling car insurance, and no one selling life insurance, there is an obvious opportunity for an apt car insurance provider to make a buck by switching to life insurance. But the fact that the life insurance niche begins to be exploited doesn't (necessarily) entail that providing car insurance suddenly becomes unprofitable.
Likewise there are many ways to make a living as an anthropoid (the group including monkeys, apes and humans, distinguished from other primates in having a well-developed collarbone, rotating shoulder joints, and partially rotating elbow joints). Just because apes evolve, doesn't make being a monkey suddenly inviable, nor does humans evolving automatically make being an ape inviable.
Your reasoning is sound, but that isn’t going to prevent your post from being flamed. Evolution seems to be just one of those subject here that evoke strong opinions. I liked your metaphor, by the way. Good luck... and here we go!
Actually, that WAS the problem, LOL!
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