According to the National Parks Service website, only 41 wolves were released into Yellowstone and it had -major- impacts on fixing the ecosystem there.(Source:

According to the National Parks Service website, only 41 wolves were released into Yellowstone and it had -major- impacts on fixing the ecosystem there.(Source: http://www.nps.gov/yell/learn/nature/wolves.htm http://www.nps.gov/yell/learn/nature/wolves.htm ) It doesn't have to be " a lot" to keep an ecosystem in balance. A species that is there, even in low numbers(near extinction) could be the thread that ecosystem balance is hanging on by. The issue with extinction is while it's natural for a few species to go extinct, due to human influence we are losing between 1,000 and 10,000 times higher than the natural extinction rate. (Source: http://wwf.panda.org/about_our_earth/biodiversity/biodiversity/ http://wwf.panda.org/about_our_earth/biodiversity/biodiversi...) We are part of the ecosystem we are damaging. You may take it for granted that animals continue to pollinate the plants you eat at dinner time. You make take it for granted that vultures cleaning up the dead prevent the spread of disease. There are many other cases of how the ecosystem is all tied together in a way that is integral to the human race's survival.