In the beginning, there were bacteria. . . . [A] nearly universal assumption is that all subsequent life descended from the original life form through a continuous chain of ancestor-descendant pairs. This assumption looks good because all living organisms share biochemical traits. It is conceivable, of course, that life originated more than once on the early earth but that all except one life form died out early, leaving a single lineage as the ancestor of life as we know it. If this did happen, it was the first important species extinction.
The technical definition of the Holocene has to do with the extinction of a snail species in Sicily.
We have no ethical obligation to preserve the different breeds of livestock produced through selective breeding One generation and out. We have no problems with the extinction of domestic animals. They are creations of human selective breeding.
It is even harder to realize that this present universe has evolved from an unspeakably unfamiliar early condition, and faces a future extinction of endless cold or intolerable heat. The more the universe seems comprehensible, the more it seems pointless.
There is a beginning and end to all life - and to all human endeavors. Species evolve and die off. Empires rise, then break apart. Businesses grow, then fold. There are no exceptions. I'm OK with all that. Yet it pains me to bear witness to the sixth great extinction, where we humans are directly responsible for the extirpation of so many wonderful creatures and invaluable indigenous cultures. It saddens me to observe the plight of our own species; we appear to be incapable of solving our problems.
Extinction is the rule. Survival is the exception.