Quote:
Originally Posted by mynah Interesting question, but a quote I read comes to mind: Man classifies, nature does not. |
Excellent and pithy.
Many folks find this a very difficult concept to get their minds around.
Nature does not recognize "species". There are no hard and fast boundaries separating one species from another. Our human-defined definitions are heuristics, or rules-of-thumb.
That two similar but distinct species should not be cross-fertile (and produce fertile progeny) works pretty well most of the time. There are many exceptions.
There are even "ring-species" mentioned in an earlier post that show that even though Animal Group A may be able to cross-breed with Animal Group B, and B may be able to cross-breed with C, it is entirely possible that Animal Groups A and C are infertile with each other.
Therefore A and C are of different species. Yet A is the same species as B is the same species as C.
