Y chromosome dying off?
This is depressing to me. lol i like my men. I know I know it prolly wont happen in my lifetime but still it is depressing. Can anyone explain to me why the Y chromosome is dying off and how long is it expected to take? Also, what are scientists developing to prevent it? Thanks.
- Culture NineLv 51 decade agoFavorite Answer
The theory behind the Y chromosome die-off is centered solely on the fact that the sex chromosome is the only ones that are not necessarily paired. When the chromosomal recombination occurs during meiosis (which corrects genetic flaws due to the fact that there is a genetic "backup"), the Y-chromosome does not have a pair to recombine with while the X-chromosome still undergoes recombination in females.
Thus the theory goes, without way to correct genetic errors introduced by mutations the genes on the Y chromosome will eventually become non-functional. (source 1)
This is supported by the fact that in most mammalian species, the Y chromosome is much shorter than the X chromosome. (source 3)
However recent studies have shown that the demise of the Y chromosome is greatly exaggerated, at least in humans. A study has shown that Y chromosome in humans have remained stable for the past 6 million years compared to the degradation seen in chimpanzee DNA (source 2), this suggests some kind of stabilizing factor for the human Y chromosome.
An interesting parallel you might want to look into (if your are interested) is mitochondrial DNA, which is like the Y chromosome in which it doesn't have a way to self correct genetic errors, except in this case it is only passed down through females of the population. (source 4)Source(s): 1. http://www.theage.com.au/articles/2004/09/05/10943... 2. http://www.sciencedaily.com/releases/2005/09/05090... 3. http://en.wikipedia.org/wiki/Y_chromosome#Shrinkin... 4. http://en.wikipedia.org/wiki/Mitochondrial_DNA
- tiger bLv 51 decade ago
I haven't heard a single thing about the y chromosome dying off, and it wouldn't matter if it did or not. There is exactly one gene that for the most part determines if you are male or female and although that gene is usually located on the y chromosome, in at least 1% of the population that has been measured, it is not.
If you know anything about genetics, you know cross-overs happen and crossovers happen with the sex genes as well as the autosomal genes (so there is 1% of males out there with XX and 1% of females with XY genotypes). Otherwise, females and males share every other gene in common (wether they are expressed or not is a different story, but you can say the same thing about the one gene that turns zygotes male as well). The loss of the Y chromosome, would not necessarily change the sex ratio (as i just explained to you) and could possibly be beneficial to males since you would no longer have to worry about sex chromosome recessive genes such as colorblindness or male patterned baldness.
- 6 years ago
when you say they are male or female can they reproduce with non standard genotypes? id say not... perhaps a person with XXY may look female or male but they cant procreate reliably... some the meiosis produces %50 viable gametes... I think to continue the species we have to transcend the primal mating ritual. too much time and energy is used. I think all the next step is isolating reproduction and making a human that does not waste resources lining a uterus with blood. the male is unable to incubate their young and fights and wastes resources winning a woman. . a human strengthened with testosterone and has no reproductive load. grow people out of body. until this is achieved we should be logical for the mission to mars and only have female adults... that way they can grow ova sent with them to populate mars