How do we define a "new" species.

Note the important difference in the these quotes. One is "a group that interbreed" that is they do interbreed the other is a group that can interbreed. Part of the biological species concept is that the breeding occurs in the wild naturally.Dogs and wolves, however, do breed naturally. In this case the incipient species has been separated out early. Remember, one species (most of the time) blends (over time) imperceptibly into the new one forming. When you decide a new one has formed is a matter of judegment. We probably separate dogs off because of non breeding reasons and because we are interested in them.Google for a definition of "species" and you will find many pages of discussion on trying to find a good definition.Remember that after species all the higher levels of taxonomy are for convenience of finding information and our tendancy to want to group things. The only "real" part of taxonomy is the commonality of descent. However, after enough time a lot of the details of that have been lost so we have trouble deciding when to split or group species under one heading or another.Why is the sterile mule in anyway "peculiar"?This message has been edited by NosyNed, 01-25-2005 20:48 AM

Maybe that will happen.It may also be that one side of the mountain was dryer and one wetter. Where they meet may have both enviroments side by side and the "dry" species will predominate in the dry areas and the "wet" in the others.Perhaps while evolving separately one has picked up on an insect common on one side and not on the other. By the time they meet they may co exist without direct competition.Or as noted above they may. In which case one may intrude on the other.What would happen if different events had taken place in the past is an interesting question. Gould suggested that with some many contingencies occuring the type of things that would evolve the next time would not be just like the ones that did last time.That is almost certainly true. However, the many instances of convergent evolution show that many things would be like what exists now. Eyes have evolved separately a bunch of times (like maybe 40). The necessity for streamlining would ensure that there would be fish shaped things in the seas even if they would not be the fishes we see.However, somethings may not happen a second time around. Intelligence has been suggested as one of them. We don't know. Well, using the word "monkies" very very losely I would have to say they did. And you're right they are much, more numerous than their cousins who didn't.

Which dog? My purely personal opinion is that dogs are already more than one species. This is just a case where the two species are close enough to produce offspring but not close enough to produce fertile offspring. I think it has been mentioned in a number of threads that speciation is not (usuall) an instantaneous thing. The "mule" case is, I'm guessing, going to happen a lot. The only reason we are more aware of this one is that we have domesticated both animals and keep them in close proximaty.

I think it is obvious but not uninteresting.For some reason this point is missed when discussion ring species.I think it was Dawkins who points out that we and chimps are "ring species" in time rather than geography. He asks what our attitude would be if the intermediaries back from each of us and chimps to the common ancestor were still around.It is only the fact that the intermediares are dead that allows us to think of ourselves as across a gulf.