The emergence of male is still a mystery

  • Guenter

    Posts: 5

    Aug 13, 2015 4:03 PM GMT
    Since the beginning of the 60s it is believed the Y-chromosome determine the sex of a child. How exactly this happens still remains a mystery.
    Moreover, at the disposal of scientists there are facts disproving the decisive role the Y chromosome in shaping masculinity. For example, there are individuals in whom the presence of both X chromosomes did not prevent them from being boys.
    Geneticists call such men reversed women, but actually they look as average boys. The matter is that: in one of their X chromosomes a section later called "Sex-determining region on Y" or SRY is embedded . Even in the absence of the entire Y-chromosome SRY has a decisive role in determining the gender.
    This area is responsible for the production of testosterone. This steroid hormone penetrates into cells of growing male fetus and binds to a protein receptor. Then the hormone and the receptor penetrate into the nuclei of cells where they both bind to DNA, and engage the genes needed to make a man.
    Many families have mutations damaging the receptor, which usually leads to the birth of a girl. However, during the process of growing, they didn't get their periods. These girls are called 'male pseudohermaphrodite'. They have one more clearly masculine trait - their height: in adulthood, they become very high.
    On photo — allegedly male pseudohermaphrodite - Pinki Pramanik
    http://imgur.com/G9z1dDW
    Until recently, the inhabitants of village Salinas, the Dominican Republic, wrongly determined the sex of some boys, considering them girls. Such cases are so common that villagers came up with a special nickname for them: 'guevedoche', or "penis at the age of twelve”. All 'guevedoches' lack the enzyme called 5-α-reductase, which converts testosterone into the more potent form 'dihydroxytestosterone', DHT. Any mutation affecting this enzyme leads to a lack of DHT and external genitalia growth disorders. Guevedoche at age 8:
    http://imgur.com/aLkRAsC
    Adult guevedoche:
    http://imgur.com/p1VpPao
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    Aug 13, 2015 8:38 PM GMT
    interesting post, thanks
    nature could have many alternate plans
    so what really are the reproductive goals?

    mate choice;
    Females (most of the time) are the choosy sex that discriminate amongst competitive males most of the time. None random process. Either female or male but a process results in the selection of the healthiest, strongest, and/or most dominant.

    cost of mating;
    males that mate often have lower probability of insuring a successful birth. Ugly effeminate boys, or sissies, are physically and verbally harassed because they dont play the game. Normally they would have more of and advantage.

    two distinct genetic models
    may reduce transmission of regressive treats.

  • Posted by a hidden member.
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    Aug 13, 2015 9:37 PM GMT
    Guenter saidThe emergence of male is still a mystery
    The existence of male is still a blessing. icon_cool.gif
  • Oceans_of_Flo...

    Posts: 393

    Aug 14, 2015 1:15 AM GMT
    Whatever, happened, I'm just glad I got the long end of the stick, if you know what I'm sayin. OP, if you get to looking anymore like Helen Mirren, I shall have to propose marriage!
    ...................
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    Aug 14, 2015 2:03 PM GMT
    avtandil saidYou are genetically healthy but still think that have some problems with size or erection? You are welcome: https://SPAM
    Hello, spammer.
    jT7fdLDTRr-7.png
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    Aug 15, 2015 9:57 AM GMT
    I recall years ago I spent an evening browsing in the private library of the Salk Institute in La Jolla where a buddy had a summer college research job. One of the books there was a treatise on the subject of the various reproductive "mistakes" which can occur, often containing illustrations either photographic or artists' renditions. It was truly amazing the number of things which can go wrong, so one needs to count one's blessings when one is born "normal," given the really untoward conditions which can happen. Given the history of adverse treatment of homosexuals whose normal and frequency incidence of approximately 10% of births, one can only feel for those born with "equipment" which radically differs from the normal, the lives they must have had to endure.