Monday, September 26, 2011


Biblical tradition tells the story of creation with man as the 1st sex, and woman the second, created from Adam’s rib.
Biology conveys a different tale for the evolution of sexes, however revealing that man, is the second sex not woman. Recent research evidences suggesting that man not only be the 2nd to arise, but the 1st to disappear.
‘Y’ in trouble
The human Y has lost 1393 of its 1438 original genes over the course of its existence. Researchers have found that, Y is degrading fast; losing genes at rate of 5 per million years and the Y will ‘self destruct’ within the next 10 million years.
Back 300 million years ago, we had no sex chromosomes, only ordinary autosomes.Then suddenly a chance mutation occurred in the ancestral Y, mutating the SOX3 to the SRY gene. The ancestral X retained the unmutated SOX3.And then sex chromosome emerged.
Between 80-300 million years ago, inversion took place in Y and the ultimate result is only 2 distal ends of X and Y remains identical known as pseudoautosomal regions. Men are basically genetically modified women. For males there is curse of the lone X.they have ended up with an array of inherited condition and diseases related to problem on the X chromosome.
What are the reasons for greater mutation in ‘Y’?
The Y chromosome is unique in human genome. It is pathetic little chromosome, gene poor, (few genes interspersed with lots of junk) prone to deletions and loss.
Human Y chromosome is passed exclusively through sperm, which undergo multiple cell division during gametogenesis each cell division provides opportunity for mutation, and sperms are stored in the highly oxidative environment of the testes which encourages further mutation. These are the reasons; put the Y at a risk of mutation greater than the rest of the genomes.
Will we have males?
Scientists have long been suspected that, y is deteriorating and could disappear entirely within the next 10 million years.
Will this be the end of evolution for humans?-if this happens it won’t be the end of males.instead, another gene takes over and new sex genes start evolving.
Will there be new sex chromosome evolution in humans?
May be it will happen in different ways in different population, and we will split in to 2 species.
But what happens if X takes another evolutionary direction and become asexual?
Unisex reproduction by females is one of the options for the survival of humanity .(Female eggs fertilized by nuclear X chromosome of another female and implanted by IVF method.Eventhough several vital genes must come from males for survival, certain Rodent species –male vole of Europe and country rat of Japan are living healthy ,have no Y and no SRY genes.
Hope for Y’s future:
Y chromosome palindromes- y has been secretly creating backup copies of its most important genes. These are stored in the DNA as mirror images or palindromes(which read the same forward and backwards)That means ,many of the genes on ‘Y’do occur as pairs-allowing the genes to repair themselves when they get damaged. Resent comparisons of the human and chimpanzee Y chromosomes show that the human y has not lost any genes since the divergence of humans and chimpanzees between 6-7 million years ago.
It has been predicted that ‘Y’ will continue to decay and lose genes. Before the ‘Y’has a chance to disappear completely, however humans will have already left the earth or perhaps they will have been brought to judgement day by the same god who created Adam in the 1st place.

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