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НазваImpact of evolution on human thought Testosterone (реферат)
РозділІноземна мова, реферати англійською, німецькою
ФорматWord Doc
Тип документуРеферат
Замовити оригінальну роботу
Farid Gazizov

Impact of evolution on human thought 


For a long period of time humans could not answer the question of what
makes a man, a man, and a women, a women.  As was recently found main
difference is not just in presence of genitals.  Probably one will ask
why?  The answer is that genitals themselves are indirect products of
another matter.  The name of this matter is testosterone.  

“Testosterone is a hormone that stimulates sexual development in male
human beings.  It belongs to a family of hormones called androgens. 
Primarily the testicles, a part of male sex glands, produce androgens. 
The ovaries in females and the adrenal glands in both sexes also yield
small amounts of testosterone and other androgens (The world book

In its earliest crucial functions, in developing embryo, testosterone
play the key role in telling the cells of the genetically male embryo to
develop as a male.  It is amazing, but all human embryo begins as
females for the first few weeks of an embryo’s life, a small group of
cells have potential to develop either as ovaries or testes.  About one
million of genes that are needed to direct the development of a human
being, one single gene (the “SRY” gene), which is carried on the Y
chromosome, is responsible for determining the sex of the embryo.  If
the embryo’s cells contain the “SRY” gene, the embryo will develop
testes, which at some point and for a limited period of time early in
its development produce and release a big amount of testosterone.   It
turn, testosterone then signal the cells of other parts of the embryo to
develop as a male.  

As shown in the study by a Stanford research group namely testosterone
is responsible for formation of genitals.  An experiment was held on
newborn female rats.  They were injected with testosterone. 
Surprisingly, but the female rats developed male genitals, and female
genitals began disappearing.  Later “converted” female rats started
revealing purely male behavior, and they were fully aware of usage of
their “new” male genitals.  The same experiment was performed with male
newborn rats.  It is amazing, but their penises withered and later
completely disappeared.  This experiment is not ethical to perform on
humans, but random facts suggest that all most the same can be done with
humans.  For instance, in lesbian couple, butches (female that
represents male) use testosterone injections to develop male features
such as deep voice, facial hair and muscles (“The He Hormone,” Andrew

In girls, the adrenal glands begin to produce testosterone earlier than
in boys.  That’s is how and why girls mature earlier, as a rule, than
boys.  It was testosterone that stimulated the growth of girls pubic
hair and underarm hair (there are testosterone receptors in the skin of
the pubic area and the skin of the underarm that are genetically
programmed to react to testosterone by producing hair).  And
testosterone stimulated girls skin to produce more oil, contributing to
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