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When you refer to dogs that were a different species. Were you saying that they were so simply because they could not reproduce? If that is what you meant that we also created a new species by breeding horses with donkeys and creating Mules. The only problem with this is that BOTH of those new species were completely unable to replicate themselves on their own and thus would be a dead us branch of evolution. Can you find ANY form of speciation that actually produces positive results? [/B]
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I think that what
CSflim meant that Evolution is 'not just a theory', but that it is currently a well understood, accepted, and thus far not scientifically refuted
Theory.
As far as the dog argument is concerned, I'm not sure how you are contradicting it. Speciation, as I understand it, is not a direct result of combining two existing species. It is beginning with one species, putting this same species in different environments and having different traits produced. This leads to sub-species, and eventually different species altogether. When these traits aren't huge, then the species can still produce viable offspring (wolves and german shepards, for example). When these species are divergent enough, or their combination will result in a genetic inconsistency (as has been tested and shown with mules), then the offspring are not viable. It is clear that horses and donkeys are related- as I understand it this means they at one time shared a common ancestor.
Many dog breeds can produce viable offspring, many can't. However all dog breeds are technically the same species, albeit with many sub-species. The common understanding is that all 'dogs' were domesticated from early wolves, and after enough domestication had enough traits differing to be classified as a separate species. In this case, sub-species of dogs qualify to be different species (and essentially are by modern dichotomy). Thus, a greyhound and a shitzu are species that can reproduce within their sub-species but certainly can't reproduce with each other; both sub-species have developed from a common ancestor as a direct result of human involvement.