The list—from the beginning of life to the present day—is far too great to give here.
The dodo bird’s story is interesting as an example because it happened recently—recently that is, in geologic time.
In the sixteenth century, sailors populated the island of Mauritius in the Indian Ocean. So did dodo birds. They were large, seemingly stupid birds that could not fly. Their extinction came about through competition among different species.
Sailors killed dodos easily for food, while the pigs and rats that came to the island with the sailors ate dodo eggs. Within one hundred years, dodos no longer existed.
The blue whale has become so rare that it is unlikely that the few individuals left will be able to meet and reproduce.