posted on Jul, 10 2008 @ 12:28 PM
I think that with pandas, they were probably evolved from an omnivorous ancestor. Most bears are omnivorous. Pandas have teeth that were obviously
designed for killing prey/tearing meat, so I think there is little doubt their ancestors ate meat in the past. I don't think it's safe to say that
they were forced to move to a vegetarian diet. They may just have found that plants were an easier option, and since little else eats bamboo they
evolved to exploit this food source.
Specialization is a risky path to take. By specializing in a particular food source, you effectively limit your options, and if that particular food
source runs into problems then you end up in trouble. That is why may species are endangered, and also because man disrupts their natural habitats.
Of course, man is not the only cause of extinctions. Nature is a fluid thing, and sometimes one species gets the upper hand on another, resulting in
the extinction of the species that can no longer effectively compete.
In the case of the panda, they are endangered because their habitat has been fragmented by man, and they need large ranges in order to survive, and
there are very few left now. So I think it's safe to say that the panda would not be endangered if it were not for man.
Other cases would have to be taken on their own individual merits, but in general I think man's interference is the cause of the majority of species
becoming extinct/endangered. In many cases, the relationships between organisms in a food web are very fragile anyway, and it may only take a little
push by man for the balance to be upset and for at least one species involved to suffer.
Interesting fact about mosquitoes there (I did not know that females were omnivorous). I agree, it does seem to be a strange way of doing things, but
it does seem to work for the mosquito! Despite massive attempts by man to eradicate it ('___' spraying campaigns, and covering all standing water with
oil to prevent the larval stage from emerging and becoming adults), they are thriving!
So despite this strangeness in their feeding habits, mossies have made a rather shrewd evolutionary move it seems. They have specialized feeding
habits, but at the same time can survive on a number of food sources, so they have left their options open enough that they are not heading into an
evolutionary dead end - at least not yet anyway!