Question of the day

What is the first evidence of a new species?

Reproductive isolation is the major working criterion for species definition. If members of two different species mate, a hybrid is produced. Hybrids usually are unable to survive because of development abnormalities that keep them from maturing. Reproductive isolation remains the major criterion in defining a species.

Reproductive compatibility Reproductive isolation Punctuated equilibrium Hardy-Weinberg equilibrium Sympatric speciation