The BIG Questions

knunan at .interramp.com knunan at .interramp.com
Tue Aug 30 02:25:09 EST 1994


re: the big question. I don't really know if there is a big
question or merely a series of small ones. Take Leishmania,
for example.  Many animals (e.g. dogs, snakes, lizards) can
serve as intermediate hosts for this hemoprotozoan but they
cannot pass it on.  Only the sand fly, and particularly
certain species of sandlies can transmit the disease between
hosts and to man. Why? That's because of the unique behavior
of the sandfly which leishmania requires to perpetuate its
life cycle. No other phlebotomine (blood-sucking) insect can
replace it. Once the sandfly acquires a dose of leishmania
from a host during a blood meal, it goes next for a sweet
meal (from flowers, for example) instead of a subsequent blood
meal as most blood sucking arthropods would do.  This unique
variance in the dietary behavior of the sandfly enables
leishmania to reproduce and engorge its salivary glands where
it can then be passed to another host.   The life cycles of
parasites are uniquely fascinating, each one individually and
uniquely.  There is no big question; only evolution, selectioo
pressures and unique life cycles that must be elucidated.
If there is a big question than it must be rooted in religious
mysticism.  I do not believe it could be otherwise. Does anyone
else have any opinions on this?



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