Question

The canary and the goldfinch are two types of birds. When they reproduce they create
another bird which is crossbred, but this bird, unlike the canary and goldfinch, cannot
reproduce. Can we say that the canary and the goldfinch are of the same species?

Answer 1

Respuesta:

No, because if they were the same species, the offspring would be fertile. One of the first terms to sort out two species is if they can reproduce and have fertile descendants.