Posted by Carlos on May 19, 1998 at 14:42:20:
In Reply to: Species vs. Genus posted by rpcman on May 19, 1998 at 14:01:12:
: However, many of these "species" do occasionally cross-breed, creating hybrids (some successful, some not).
: By "some successful" do you mean that some of the hybrids can reproduce while the others are sterile?
No, by successful I meant hybridizations that continue to be separate and distinct from their "parents", instead of disappearing after a few generations. As I recall, there was no indication that any of the hybrids were sterile.
: Since they can interbreed (even if they don't normally do so), I'm not sure that they fall under the strict definition of "species".
: I think they would still be distinct species of the same genus (if they didn't normally reproduce and if the product when they do is frequently sterile).
As you know from reading the Talk-Origins discussion on speciation, there is considerable controversy over what constitutes a "species". Perhaps because I understand it better, in my mind I have always considered "species" to be reproductively isolated. By that definition, since the Galapagos finches can produce non-sterile hybrids, they don't consitute separate species. However, under other definitions they are separate species.
Here, again, is the speciation link for all to enjoy.