The purpose of zoos

In my last blog I touched upon some arguements that can compare zoos with pornography. While some of these arguements tried to stretch it and really make the arguement strong, I never really saw it hold true, nor did I really believe the arguement.
On a personal level I feel zoos are an educational experience. Sure there are plenty of people out there that will say a zoo is an explotation of animals, and we hold them captive against their will, and they are being held outside of their natural habitat. While I agree that they are being held outside of their natural habitat, and they are to a certain degree being held captive, it is for educational purposes. They are not being experimented on, and in some cases, zoos hold the only kinds of some speicies still alive on the planet.
If you refer back to my posting on rights concerning humans vs. animals. I believe that it comes down to who is stronger and has more power to determine who has more of the rights. Do animals have the right to be in the wild, sure, but the wild is also a dangerous place for some animals, and for some species, they have become extinct, and for other species who are endangered, they are extinct in the wild, but still exist in zoos. Humans are expanding their world, and it is becoming a danger for animals, and many animals are being displaced in the wild. Zoos become a safe haven for animals.