Extinction is nothing new … mass extinctions are part of the life cycle of the planet. Still, if we are indeed in the 6th great mass extinction then perhaps we should be worried that at least one such mass extinction took the planet 30 million years to recover from!
Some animals such as the Tasmanian Devils down under are threatened by diseases but many have humans to thank in some form or another for their extinction. Many of these species few people ever know about.
Perhaps even more troubling than increased animal extinctions are the disappearances of plants that we rely on (or might rely on in the future) to produce invaluable medicines.