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The Importance of Sex
Sex is one of the reasons we have
evolved into the most intelligently advanced life form on the planet.
Sexual reproduction is defined as "the processes of gene recombination
leading to reproduction." This gene recombination promotes genetic
variation among offspring.
Genes, carried by every cell in
our body, hold the code that helps determine what we become: how
many fingers we have, what color eyes we have, our height, the natural
texture and color of our hair, the size of our feet etc. In addition
to effecting our appearance, we are starting to understand how genes
can effect our behavior. Now, I'm going to temporarily simplify
human genetics for the sake of explanation. Genes come in pairs.
So lets say a mother has an "eye color" gene coded for blue. She
would also have another "eye color" gene and let's say it's
coded for brown. These genes are a pair because, although they are
coded differently, they are coded for the same part of the body.
Every gene we have is paired with another in this manner. For each
pair only one is expressed. In this case, lets say the brown gene
dominates over the blue gene so only the brown gene is expressed,
giving the mother brown eyes. Now it's only a matter of chance
which gene of the pair is given to the child. So one child of the
mother might receive a "brown eyed" gene while another child of
the same mother might receive a "blue eyed" gene. In addition it's
just a matter of chance which gene the child receives from the "eye
color" genes of the father. This produces children with different
eye colors. The same differentiation occurs with every other gene
in the child's genetic makeup.
Without the existence of sex,
we wouldn't be conceived by the combination of genes between
two parents. If sex didn't exist, we would have to acquire all
our genetic material from a single parent making us identical clones
of that parent. A few genes here and there might mutate due to radiation
or some other mutagenic factor, but for the most part, we would
be replicas of our parents. If sex never existed, our parents would
be replicas of their parents. We would all be the cloned descendants
of the first human, and thus would all be identical to each other.
Furthermore, without the genetic variation supplied by sex through
evolution, we would probably still be simple organisms squirming
around in the ocean (to be explained in the next paragraph). What
a screwed up world this would be without sex!
Fortunately since sex has been
a fact of life for millions of years, the genetic variation that
sex provides has helped us evolve as a species. If individuals of
a population have varying characteristics, then some individuals
will have characteristics which make them better fit for survival.
As a result these "fit" individuals will survive longer and more
successfully allowing them to reproduce more. This will cause more
of the overall population to acquire those beneficial characteristics.
Thus the population as a whole will be better fit for survival.
This process, called "natural selection," allowed our species to
adapt to the Earth's environment by change over time or "evolving"
into the successful highly intelligent human life forms we are today.
Thank goodness for Sex!

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