Human male: A degenerative sex

Chromosomes are long, stringy aggregates of genes that carry heredity information. They are composed of DNA and proteins and are located within the nucleus of our cells. Chromosomes determine everything from hair color and eye color to sex. Whether you are a male or female depends on the presence or absence of certain chromosomes.

Diagram (courtesy: wikipedia.org) of a replicated and condensed metaphase eukaryotic chromosome. (1) Chromatid – one of the two identical parts of the chromosome after S phase. (2) Centromere – the point where the two chromatids touch, and where the microtubules attach. (3) Short arm. (4) Long arm

 Human cells contain 23 pairs of chromosomes for a total of 46. There are 22 pairs of autosomes and one pair of sex chromosomes. The sex chromosomes are the X chromosome and the Y chromosome.

Sex chromosome evolution: Sex chromosomes are derived from ordinary autosomes. The X chromosome is thought to maintain most of its ancestral genes over evolutionary time, whereas its Y counterpart degenerates, owing to its lack of recombination. Genomic analyses of young sex chromosome pairs support this view and have shed light on the evolutionary processes underlying loss of gene function on the Y. Studies of ancestral sex chromosomes, however, have also revealed that the process of sex chromosome evolution can be more dynamic than traditionally appreciated. In particular, ancient Y-chromosomes are characterized not only by a loss of genes relative to the X but also by recurrent gains of individual genes or genomic regions, and they often accumulate genes beneficial to males. Furthermore, X chromosomes are not passive players in this evolutionary process but respond both to their sex-biased transmission and to Y-chromosome degeneration, through feminization and the evolution of dosage compensation.

The Y chromosome is one of the 2 sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 50 million base pairs.

The Y chromosome is the shortest chromosome in humans, and most of the Y chromosome is believed to be made of junk DNA. In the 1960s, Ohno proposed that the human Y chromosome is a profoundly degenerated X chromosome with very few genes on it encoding male-specific features and some began to speculate that the continued degradation of the Y chromosome might result in the extinction of the human male. 

The human X and Y chromosomes can use recombination to renew only their pseudoautosomal regions.

In order to address this question, it is helpful to know the origin of the Y chromosome. Surprisingly, the most primitive Y chromosome found so far was not found in any animal, but in the papaya (Carica papaya, 2n=18). Liu et al. (2004) found that male and hermaphrodite papayas contain an allele that is not found in female papayas. Severe recombination suppression and DNA sequence degeneration are observed in the regions around that allele. Although no heteromorphic chromosomes in papayas were found to be analogous to the X and Y chromosomes in humans, the newly discovered gene shares many characteristics with male-specific region of the Y chromosome (MSY).

Shrinking theory: The human Y chromosome has lost 1,393 of its 1,438 original genes over the course of its existence. With a rate of genetic loss of 4.6 genes per million years, the Y chromosome may potentially lose complete function within the next 10 million years. Comparative genomic analysis, however, reveals that many mammalian species are experiencing a similar loss of function in their heterozygous sex chromosome. Degeneration may simply be the fate of all nonrecombining sex chromosomes due to three common evolutionary forces: high mutation rate, inefficient selection and genetic drift.

pic courtesy: Daniel Berehulak/nytimes.com, December 23, 2012. New Delhi, India.

The degeneration of man as a species is already apparent.We now have Down's, muscular dystrophy, early heart failure, fiends that rape and murder small children, etc. Over 7,000 genetic faults are catalogued. If allowed to become more wide-spread, the genetic diseases now in our gene pool could end civilization. No significant gene shift is required, only a continued multiplication of the genetic faults we already have.(pic: A protester at a demonstration over the Indian government’s handling of rape cases braced herself against the spray of a water cannon fired by the police.)

Future evolution: 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. Several species of rodent in the sister families Muridae and Cricetidae have reached these stages.

Sex in the future: In modern society, where male and female are considered equal and interchangeable, the female may, and is encouraged to do so, perform all of the male tasks along with her own. She may not only bear and raise the children but provide the livelihood as well. The male, deprived of his contribution to the family and his particular contribution to society, is no longer necessary. Modern feminists envision eliminating the male completely through cloning. For some strange reason, the modern male has accepted these terms and is now little more than a stud, servicing any needy heterosexual female who happens along, or the lesbian who wishes to become pregnant. He may now act as the juvenile male, chasing all comers, all of his life, without cultural censure.

Modern cultural style dictates that the female become more masculine, complete with coarse and suggestive language and the male more feminine, complete with jewelry, carefully disarranged hair and a propensity to weep openly at the slightest provocation A result of this new independence (almost open war) between the sexes and the idea that sex is interchangeable, is a decided increase in homosexual activity. The local motel, which at one time was the noontime hotbed for sinning heterosexuals, now caters all week to same sex couples.

From the new cultural viewpoint, the male will become useless baggage. With the female propensity for a feminist society, one which must constantly guard against male domination, and with the handy tool of abortion for sex selection, the male will be tolerated only in limited numbers. Through female cloning the male may be eliminated entirely.

On the other hand, the fetus, during gestation in the womb, is susceptible to widespread damage. Modern females are careless about their living style, casually aborting a fetus at will, imbibing in alcohol, tobacco and drugs and otherwise living a stressful life style. All of this effects the quality of the new human. As an alternative to a female culture, the male could develope artificial wombs that would provide near perfect environments for the fetus. Then by cloning the male, the female could be eliminated.

Perhaps the end goal is to abandon sexual reproduction altogether. The human then becomes a self-impregnating hermaphrodite. Each child would be a clone of the parent. Evolution would have then gone full circle. The genetic and social advantages are many. The species can then become truly an intellectual species. Concerts could again become events for the enjoyment of music instead of tools for seduction. Cultures would be greatly simplified. 

#image share courtesy: ubc.ca, onelife.com, bbc.co.uk, wikipedia.org