isolation
When the members of two populations cannot interbreed and produce fertile offspring.
no, dogs and cats are two different species and cannot interbreed.
They are both considered separate species at the point they can no longer interbreed and produce fertile offspring.
No, rattlesnakes and rat snakes cannot interbreed.
When the two populations can no longer interbreed.
It is impossible. They are two different species of animals and cannot interbreed.
reproductive isolation
No, rattlesnakes and rat snakes cannot interbreed.
Taxonomy
It's the natural process of species separating from other species. Two different species cannot interbreed.
No. Humans cannot interbreed with other species.