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Author Topic: What possible use is the Y chromosome?  (Read 2810 times)

Offline John Chapman

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What possible use is the Y chromosome?
« on: 15/03/2009 18:17:43 »
Why do we need separate genders? Whenever I hear this question asked the answer always involves the advantages of mixing up the genes of two parents, as opposed to some sort of asexual reproduction which produces clones. A good answer - but not to the question I am asking! What I want to know is why does each parent need to be a different gender? Why can’t two XX genotypes mix their DNA to produce another XX genotype?

I know this would result in a population of humans who can’t park cars in spaces shorter than a runway and place cushions on every available surface, but just think of the potential partners everyone would have. And it would all be girl-on-girl action (although there’d be no guys around to appreciate it). Genders seem such an unnecessarily complicated idea. And since our distant forebearers were single celled organisms, when was this ‘boy & girl’ malarkey first thought of?



 

Offline Chemistry4me

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What possible use is the Y chromosome?
« Reply #1 on: 16/03/2009 05:22:10 »
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About 1 in 20,000 men has no Y chromosome, instead having 2 Xs. This means that in the United States there are about 7,500 men without a Y chromosome. The equivalent situation - females who have XY instead of XX chromosomes - can occur for a variety of reasons and overall is similar in frequency.

http://www.isna.org/faq/y_chromosome
 

Offline RD

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What possible use is the Y chromosome?
« Reply #2 on: 16/03/2009 12:53:20 »
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A major question is why sexual reproduction persists when parthenogenesis appears in some ways to be a superior form of reproduction. Contemporary evolutionary thought proposes some explanations. It may be due to selection pressure on the clade itself—the ability for a population to radiate more rapidly in response to a changing environment through sexual recombination than parthenogenesis allows. Alternatively, sexual reproduction may allow for the "ratcheting" of evolutionary speed as one clade competes with another for a limited resource.
http://en.wikipedia.org/wiki/Sexual_reproduction

 

Offline John Chapman

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What possible use is the Y chromosome?
« Reply #3 on: 16/03/2009 18:44:25 »
Aha! RD you've fallen into my cunningly laid trap.


Whenever I hear this question asked the answer always involves the advantages of mixing up the genes of two parents, as opposed to some sort of asexual reproduction which produces clones. A good answer - but not to the question I am asking!


As my grandson said to me yesterday after eating my Easter egg

Nah nah nanah nah   :P

What I want to know is why can't two people of the same sex produce offspring by sexual reproduction. At the moment it seems to me that the only reason we need the Y chromosome is to randomly produce more males and females. It's self fulfilling. A closed loop. Why did it evolve in the first place?
 
 

Offline Madidus_Scientia

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What possible use is the Y chromosome?
« Reply #4 on: 16/03/2009 18:52:41 »
Perhaps a species can survive better with 2 slightly different versions of itself working together, each performing their role. For example, women are excellent at giving birth to children, producing breast milk, etc. However they are somewhat vulnerable in this situation. But a male is strong and agile and can protect and provide food for her and the baby.
 

Offline John Chapman

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What possible use is the Y chromosome?
« Reply #5 on: 16/03/2009 19:25:10 »
Hi Chem4Me

That's a really interesting article you've found.

Quote from: Chem4Me's article

....we have genes on the Y that can turn females with XX chromosomes into males and genes on the X that can turn males with XY chromosomes into females… wow! Maleness and femaleness are NOT determined by having an X or a Y, since switching a couple of genes around can turn things upside down.


I'm going to have to edit the title of this question now! >:(  Although I still want to know why we need two sexes, regardless of how genders are created.
 

Offline John Chapman

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What possible use is the Y chromosome?
« Reply #6 on: 16/03/2009 20:26:12 »
Hi Madidus_Scientia

That's a very good point. I hadn't thought about one parent being the carer and the other the provider. Also, I suppose historically if both parents were able to get pregnant and did who would bring home the mammoth steaks?
 

Offline rex789

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What possible use is the Y chromosome?
« Reply #7 on: 18/03/2009 17:43:56 »
we need two sexes because men are from mars and women from venus!

i would say genetic vatiation. and you will say there are other way other than sex. i would reply they are not as good. what does sex do? if effectively doubles a species genetic pool and it's change of survival. ok so not lets see....

an earth full of women, that would be too bad. untill there was a worldwide breakdown of cars and then none would know how to fix them. however if there were men they would fix the cars.

basically instead of having one model of the species going thru evolution you have two of the same species going thru evolution and with a slightly diff set of genes and rules. (yes x and y have some differences and the way they behave in male vs female progeny).
so now you can see that a species with male and females going thru a stress would come out more varried that a species that only has one sex 'womale'.
 

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What possible use is the Y chromosome?
« Reply #7 on: 18/03/2009 17:43:56 »

 

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