[Oberon]

Creationists don't accept them because a lizard is still a lizard and a fern is still a fern. But they came from one population that has split and no longer interbreeds. According to evolutionary biologists, that's how speciation begins.

The two populations may no longer interbreed, but to me the more important question is this: Are they cross-fertile, and would they produce fertile offspring?

If they have the same number of chromosomes and would produce fertile offspring, I submit to you that they are the same species.

[<1/1,000,000th%]

The two populations may no longer interbreed, but to me the more important question is this: Are they cross-fertile, and would they produce fertile offspring?

Do you mean like ligers or mules? With enough technology you can cross anything. Look at all the weird lab mice strains running around. Some have human immune systems or human brain cells. ;(

In evolutionary biology, the important first step to speciation is that 2 populations rarely, or don't, crossbreed. That's what allows them to develop separate characteristics and eventually become morphologically distinct and unable to cross-breed.

Your requirements are not part of evolutionary theory.

[<1/1,000,000th%]

If they have the same number of chromosomes and would produce fertile offspring, I submit to you that they are the same species.

I agree. Species can be defined that way.