LiveScience: It is tricky to measure the number of species going extinct each year on our planet -- it all depends on how many species of flora and fauna exist, a difficult number to pin down. What most scientists can agree on, however, is that the extinction rate is 1,000 to 10,000 times higher than it would be if people weren't around.
While those changes don't appear to impact our everyday lives -- the extinction of a little-known tree frog doesn't change how long we wait in line for our morning coffee...