Increase genetic variation among species came about as a result of

It is as a result of Genetic Mutation.

Explanation:

Mutation and sexual reproduction result in increased genetic variation.

Mutation is the change in genetic content or DNA of an organism. It can be as a result of mutagens or errors during DNA replication. When there is mutation in reproductive cells such as sperm or egg, it can be pass to the next generation. The new traits will become permanent if it is subject to natural selection.

Sexual reproduction involves the transfer of new genes from the parents and to the offsprings which lead to new phenotypes and these can help the organism to adapt to it's environment.

true is the

a bird that nests only in a particular tree species.