The future of the Y Chromosome

[A.R.Amistad]

Wiki

Future evolution of Y Chromosome


In the terminal stages of the degeneration of the Y chromosome, other chromosomes increasingly take over genes and functions formerly associated with it. Finally, the Y chromosome disappears entirely, and a new sex-determining system arises.[16] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Graves.2C_J._A._M_2006-15) Several species of rodent (http://en.wikipedia.org/wiki/Rodent) in the sister families Muridae (http://en.wikipedia.org/wiki/Muridae) and Cricetidae (http://en.wikipedia.org/wiki/Cricetidae) have reached these stages,[17] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-16)[18] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-17) in the following ways:


The Transcaucasian mole vole (http://en.wikipedia.org/wiki/Transcaucasian_Mole_Vole), Ellobius lutescens, the Zaisan mole vole (http://en.wikipedia.org/wiki/Zaisan_Mole_Vole), Ellobius tancrei, and the Japanese spinous country rats Tokudaia osimensis (http://en.wikipedia.org/wiki/Tokudaia_osimensis) and Tokudaia muenninki (http://en.wikipedia.org/wiki/Tokudaia_muenninki), have lost the Y chromosome and SRY (http://en.wikipedia.org/wiki/SRY) entirely.[19] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-18)[20] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Graves_2006-19)[21] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-20) Tokudaia (http://en.wikipedia.org/wiki/Tokudaia) spp. have relocated some other genes ancestrally present on the Y chromosome to the X chromosome.[22] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Arakawa_et_al._2002-21) Both genders of Tokudaia spp. and Ellobius lutescens have an XO genotype,[22] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Arakawa_et_al._2002-21) whereas all Ellobius tancrei possess an XX genotype.[20] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Graves_2006-19) The new sex-determining system for these rodents remains unclear.
The wood lemming (http://en.wikipedia.org/wiki/Wood_lemming) Myopus schisticolor, the arctic lemming (http://en.wikipedia.org/wiki/Arctic_lemming), Dicrostonyx torquatus, and multiple species in the grass mouse genus Akodon (http://en.wikipedia.org/wiki/Akodon) have evolved fertile females who possess the genotype generally coding for males, XY, in addition to the ancestral XX female, through a variety of modifications to the X and Y chromosomes.[23] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-22)[24] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-23)[25] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-24)
In the creeping vole (http://en.wikipedia.org/wiki/Creeping_Vole), Microtus oregoni, the females, with just one X chromosome each, produce X gametes only, and the males, XY, produce Y gametes, or gametes devoid of any sex chromosome, through nondisjunction (http://en.wikipedia.org/wiki/Nondisjunction).[26] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-25)

Outside of the rodent family, the black muntjac (http://en.wikipedia.org/wiki/Black_muntjac), Muntiacus crinifrons, evolved new X and Y chromosomes through fusions of the ancestral sex chromosomes and autosomes (http://en.wikipedia.org/wiki/Autosomes).[27] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-26) Primate Y chromosomes, including in humans, have degenerated so much that primates will also evolve new sex determination systems relatively soon, in about 14 million years in humans.[16] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-Graves.2C_J._A._M_2006-15)[28] (http://en.wikipedia.org/wiki/Y_chromosome#cite_note-27)



I think this is very interesting, and is a great argument against anti-homosexual bigots who think that homosexuality will "decrease birth." Turns out we don't even need the Y chromosome to survive. :D

[Mumbles]

http://staff.um.edu.mt/acus1/Mendel1-web_files/image004.jpg

Given the possibility of trans-location of genetic material over time, it may truly be possible for the X chromosome to get all the information of the Y seeing how small it is in comparison. But you have to remember how much information is contained in such a tiny thing, because the nucleotides are even smaller. So it won't be anytime soon, as stated in the article "14 million years". But there's still that possibility, given time.

There are entire species that are asexual, why not humans?

[Dimentio]

I think it is a bit worrying. While it is possible that it is a natural process, there is also a possibility that this deterioration is caused by chemical waste or unnatural food ingredients, which could also affect human beings in previously unknown ways.

[A.R.Amistad]

And animals that don't possess the Y chromosome can still have sex for pleasure! It just won't be necessary for reproduction, it will be a thoroughly emotional act. I think the Okinawa Spiny Rat, which has no Y chromosome, still engages in sex. I could be wrong, but obviously the Y chromosome is not necessary for sexual pleasure, so its not like sex would dissapear ( a nightmare that would be for sure! :scared:) I know it won't happen for millions of years, but it does say a lot of good things about gender relations, sex and homosexuality in nature.

[Dimentio]

How are mammals which do not have any male gender really procreating? *just out of curiousity since I don't think they are hermaphrodites*

[Mumbles]

http://en.wikipedia.org/wiki/Parthenogenesis

From what I understand and applying what I learned last semester in Biology, instead of creating a gamete with only one set of chromosomes to be met with and bonded to another gamete to form a complete cell, the animal just produces a whole cell in its ovary so that it then starts reproducing itself and attaches to the womb/goes into a shell and just makes a whole new being like that.

[Yazman]

What people dont realise, and I've seen in Dimentio's post, is that this doesn't mean there won't be any males. It just means the selection criteria for male/female may be/become different.

[Endomorphian]

Fourteen million years? Synthetic evolution will be a reality in the near future.

[x371322]

Come to think of it, won't we have evolved into something entirely different by then, 14 million years?

[CartCollector]

From what I understand and applying what I learned last semester in Biology, instead of creating a gamete with only one set of chromosomes to be met with and bonded to another gamete to form a complete cell, the animal just produces a whole cell in its ovary so that it then starts reproducing itself and attaches to the womb/goes into a shell and just makes a whole new being like that.The problem is that asexual reproduction isn't evolutionarily advantageous. There's a reason that sexes evolved- sexual reproduction helps spread advantageous mutations faster than asexual reproduction and also prevents the spread of disadvantageous mutations. Going back to one gender would be impossible for this reason, as asexual reproduction has less evolutionary advantages. So no I don't think that's what's happening with the rats. I think it's just that the way their sex is encoded is changing.
By the way, here's a video that shows how sexual reproduction is advantageous with an experiment:
http://www.youtube.com/watch?v=YpOSQz3m_s0

[A.R.Amistad]

What people dont realise, and I've seen in Dimentio's post, is that this doesn't mean there won't be any males. It just means the selection criteria for male/female may be/become different.

exactly. there are still male spiny okinawa rats, just no Y chromosome among them.

[Glenn Beck]

In 14 million years we'll either be extinct or growing our kids in vats so I'm gonna go ahead and not worry so much about this.

[Mumbles]

The problem is that asexual reproduction isn't evolutionarily advantageous. There's a reason that sexes evolved- sexual reproduction helps spread advantageous mutations faster than asexual reproduction and also prevents the spread of disadvantageous mutations. Going back to one gender would be impossible for this reason, as asexual reproduction has less evolutionary advantages. So no I don't think that's what's happening with the rats. I think it's just that the way their sex is encoded is changing.
By the way, here's a video that shows how sexual reproduction is advantageous with an experiment:
YpOSQz3m_s0

This is an excellent point. Thanks for bringing it up.

But it still is possible for the reproduction to occur in such a fashion, it's just not beneficial as has been pointed out.

[Lord Testicles]

The problem is that asexual reproduction isn't evolutionarily advantageous. There's a reason that sexes evolved- sexual reproduction helps spread advantageous mutations faster than asexual reproduction and also prevents the spread of disadvantageous mutations. Going back to one gender would be impossible for this reason, as asexual reproduction has less evolutionary advantages. So no I don't think that's what's happening with the rats. I think it's just that the way their sex is encoded is changing.


But asexual reproduction has the advantage that the entire population can reproduce as opposed to only half in sexual reproduction.

[A.R.Amistad]

But asexual reproduction has the advantage that the entire population can reproduce as opposed to only half in sexual reproduction.

Good point, but couldn't that lead to overpopulation?

[Mumbles]

Good point, but couldn't that lead to overpopulation?

It most likely would, but then the criteria for survival would be more strict. Survival of the fittest on nightmare mode.

[Dooga Aetrus Blackrazor]

That's bad. Scientifically speaking, I think evolution will become obsolete in a certain light. Not as a theory, and it will still apply. But I think our method of evolving will be self-directed. Genetic manipulation through science is preferable to letting society overpopulate and seeing who dies. In my view, at least.

[Ocean Seal]

I think this is very interesting, and is a great argument against anti-homosexual bigots who think that homosexuality will "decrease birth." Turns out we don't even need the Y chromosome to survive. :D
The birth rate should go down it is beneficial for all of us.

[Quail]

Asexual reproduction produces less variation in the combinations of different genes so even if we could all reproduce, our life-cycle is too long to make it advantageous. It works for bacteria (for example) because they reproduce very quickly and so random mutations work as a way of evolving. Perhaps the way our chromosomes are arranged will work, but I don't think that we would evolve asexual reproduction because it would be a disadvantage for the survival of our species.

[Weezer]

Technology has made evolution obsolete. Within the next 2000 years, we should have the technology to carve the path of evolution as we please.

Besides in the next 14 million year humans will either be extinct or have evolved into another species, or multiple species.

[Yazman]

Technology hasn't made evolution obsolete at all. It has just significantly changed selective pressures on the population, while also reducing the intensity of their impact.