Why are we born . . . . . . Young ??
An intriguing question that was recently asked by one of the scientists at my departmental retreat. Although simply stated I believe this is a rather important question that would be asked by several biologists . If you look deeply into the question it has two aspects to it.
The first one is the basic question of being
born at all. Why does life have to propagate and why at all do species give rise
to progeny. A simple answer would be that genetic information needs to be propagated
and maintained and there is natural adaptation in response the changing
environment which could lead to the "survival of the fittest". With
increasing age and individual accumulates several harmful signals such as
mutations, Telomere shortening, accumulation of Reactive Oxygen Species etc, just to mention a few
of these defects, .that eventually lead to aberrant cellular programming and
eventually death . But what if we could find ways to counteract these phenomenon?
What id nature evolved to counteract these mechanisms? why do these exist at
all? I earlier stated that being born or giving rise to healthy progeny could
be a counter mechanism to adapt to the changing environments. But what changes
the environment and I guess most of we know the answer to that, it's us the
humans. So why did is nature not selecting against a species that could
eventually be the cause of all chaos.
Speaking of evolution, just to
bring up a point, I would not lose this opportunity to mention another aspect
of evolution. There still exist several primitive species that have specific
mechanisms that id acquired by a higher species might lead to the better
survival. E.g. the long life span of turtles, the cancer fighting properties of
snake venom etc. and we are still trying to understand why humans evolved in
the first place and for how long could the species survive without disturbing
the balance of nature.
What if we were able to create an
individual with all the suitable characteristics to live for a 1000 years(or
even more) would it still be necessary for life to propagate via reproduction
and both? Would this individual not survive that long or could it be possible
that such people cold actually have evolved and present amongst us without
getting noticed..constantly moving... could they have witnessed or been Gods
themselves because of the loss of aging and degeneration over years and the
scientific knowledge lacking at the time, to understand this phenomenon.
Well, considering that the
existing mechanism of reproduction and propagation is the most efficient and
effective method evolved for persistence of life, I would then like to move on
to the second part of my question as to why we are born young or for that
matter any birth means the emergence of a new and young individual, but why
young? To answer this I would like you to consider a continuously accumulating
system. What is to stop the earth from getting overpopulated and eventual
depletion of all natural resources? So I believe that being born young could
have several reasons to it: (1) It has been shown experimentally that aging can
be reversed or so to say the human cells could be reverted to a healthier and
younger state. Being young means having fresh a fresh cellular milieu leading
to less number of cells to begin with and therefore less DNA damage, mutation,
telomere shortening etc., meaning a more healthier state over all. (2) There is
also a time delay to sexual maturation.. again why?? probably to get the right
body mass and size.. but could this also not be a mechanism to check on the
population size allowing only a certain number of individuals to be present in
the restricted availability of natural resources... but in any case the current
population numbers tends to overrule
this. Coming back to the question of being born young... If all of these
arguments hold true then why is a young one not born earlier and has to undergo
gestation for a certain amount of time inside the womb and why did nature
select it this way and not anything else??
Well there is plenty of food for
thought here and i assume that its time that scientists would want to give a
second look into the biology of different organisms to decide for themselves
alternate mechanisms that could have been present and lost during natural
selection or advantageous characteristics of the biology of young organisms.
After all we are still evolving and looking back in time could give us a
glimpse of the future.. or at least we could predict and be prepared several
possibilities to be ready for what evolution might bring our way in years to
come.
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