Answer:
natural selection causes extinction. The species that are unable to adapt to environmental changes become extinct. This reduces biodiversity.
Human activity also causes extinction. The overhunting of the American Bison, almost resulted in the extinction of this animal.
The dodo bird, passenger pigeon, and other animals.
The wild horses of the outer banks of North Carolina are in danger of becoming extinct as their range of is being reduced by encroaching housing developments. The destruction of environments by human activities is a cause of extinctions.
Genetic collapse is another cause of extinction. Species that are too closely interbreed can go extinct as mistakes in the DNA accumulate in the population.
All forms of extinction cause reductions in the remaining biodiversity .