The parasitic arms race
Though it may appear to some that we feel secure in our
domination over nature it is important on occasion to recall that this was not
always the case. Certainly the news of late should serve as a reminder to this.
Throughout all of the kingdoms of life that have ever existed on Earth there
has been an ongoing arms race the prize of which is survival. This arms race
has left within each us all a lasting legacy of immunologic memory of
biological battles fought well before anyone alive was ever born.
In a previous creatures log “the realms of the very small” I
wrote about the microscopic creatures such as demodex that make themselves at
home upon the surface of our bodies. For the most part these fellow travelers tend
to cause us no harm. There are however whole legions of viruses, bacteria and parasites
that are far less benign. As early man wandered around the coasts until he
literally walk out of Africa into Eurasia he took with him only the parasites
that came along for the journey. However there in the African cradle of human
evolution there remains in the environment hosts of creatures that evolved
specifically to parasitize us.
Ebola was discovered by the outside world only in 1976. Hidden
there on the fringes of man’s territory it had surely lingered for millennia. Since
that time in contained remote areas in central Africa there have been limited
outbreaks in which entire villages have fallen in its wake. In the decades since
it has elicited within us a nascent fear. Reminiscent of all the plagues of our
nightmares it kills indiscriminately as jumps from host to host.Here in the west perhaps because we live far from the region
of our natural evolution we erroneously feel we have had little to fear from
our ancient nemesis. However there are no more “contained areas”, for anywhere
in the world is now accessible within a day’s time. As our populations swell
and technology everyday makes the world a little smaller, we should abandon
this notion of invincibility in the face of a very old and sophisticated enemy.
A heart effected by Chagas disease
http://phenomena.nationalgeographic.com/2010/02/14/genes-from-chagas-parasite-can-transfer-to-humans-and-be-passed-on-to-children/
http://phenomena.nationalgeographic.com/2010/02/14/genes-from-chagas-parasite-can-transfer-to-humans-and-be-passed-on-to-children/
Are we headed toward a perfect storm to which we will one
day become extinct like all previous occupants of the top of the food chain
throne? I would say not. The plagues that have for eons besieged our bodies are
doing just as nature had evolved them to do and they have done it well. However
despite this almost constant battle, along the way humans have not only
survived but have thrived. Hidden within each of us transcribed within the
strands of our DNA is the story of many a hard fought battle of survival. The
evidence of which can be seen in the traces of parasitic bacterial and viral
DNA sequences that abound intermingled with our native code. Some of these
splices possibly date back to the beginnings of life on earth. These battles
have undoubtedly influenced our own evolution. Some of these subsequent adaptations may have
greatly improved our survivability. However we should not fool ourselves that
we should go unscathed this time. We will survive as we have done before. This time we possess the advantage of foresight.
Armed with the latest that medical science can
provide we should take the responsibility to do all we can. We must remember while doing so to maintain a
healthy respect for our enemy and an eye on our own frailty.
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