ROLE
OF PARASITES IN EARTH’S BIOSPHERE
Post #13
Donald
A. Windsor
Restriction
of monocultures is the basic mechanism operating Earth’s biosphere.
When
competition and predation do not control monocultures, parasitic
diseases step in. The result is biodiversity and multiple
ecosystems.
This
simple explanation is based on observation. Monocultures, such as
those planted by farmers, are quickly invaded by other species and
attacked by numerous pests. Farmers have to be very diligent to
protect their crops by using pesticides. Even then, other species
manage to invade.
Our
biosphere here on Earth is characterized by biodiversity, huge
numbers of different species and interactions among all those
species. Monocultures are rare and short-lived, found on newly
formed islands and on disturbances leading to bare earth.
But
what about life on other worlds? Does extraterrestrial life express
itself as biodiversity or as monocultures? Do other worldly species
interact in ecosystems? Or just dwell in monocultures?
Life
on Earth is analogous to human economic forces. Without governmental
regulation, unbridled capitalism results in a few very rich winners
and vast hordes of poor losers. Our era of the robber barons in the
late 1800s and early 1900s is a prime example. Parasites are similar
to governmental regulations; they stifle exuberance.
Perhaps
a world without parasites would be similar to unregulated capitalism,
with a few very successful species and no or very few other species.
Perhaps a middle class of species would have developed.
In
the near future we may get an opportunity to discover
extraterrestrial life. Will it be biodiverse? Or monoculturalistic?
If parasites are present, so too will be biodiversity.
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