conservation of species

i've recently started to work/volunteer/get credit for helping the US Geological Survey in their black-footed ferret conservation project. this is great work and giving me a wonderful connection with the organization, but has brought to my attention the conservation of species as an ethical issue. is it ethical for humans to interfere and save a species from extinction? even if it is not necessarily due to humans that the animal is headed towards extinction?

in my opinion, saving a species isn't really a bad thing. but because of the nature of evolution and natural selection, some species naturally evolve towards extinction. take the panda for example. humans have nothing to do with this animal's lack of sex drive. but they're big and cute and easy to raise money to save. as a small child i think someone gave me an "adopted panda" for my birthday.

another issue with saving a species from the brink has to do with genetic variation. 3 species in North America have been saved by capturing all remaining wild animals and breeding them captively - the red wolf, the California condor, and the black-footed ferret. the ferrets, for example, numbered 14 when they were removed from the wild, and though the population has been meticulously managed, inbreeding is unavoidable. so even though the actual current population is in the hundreds, the effective population (or the population of genetically dissimilar individuals that are breeding) is probably in the 20s somewhere. as another example; the entire population of cheetahs is so similar genetically, so recessive/homozygous, that they might as well be clones of each other.

in the case of the ferrets, humans definitely had an impact on their decline - habitat loss, systematic destruction of prey species (prairie dogs were viewed as pests) and plague arriving and spreading across the country were all because of the presence of humans.

so yes, i think saving species and maintaining as much biodiversity as we can (considering how much we have caused it to decline) is a good idea. mom always said i was a tree-hugger :)