Hi all,

I realize evolution takes a long time, so we may have not yet done anything to truly change species (Cows and Buffalos, for example). Have we ever, even on the smallest scale (drosophila?), artifically selected creatures to the extent that they can no longer breed with their progenitors?

My question is, more suscinctly, have we ever seen a speciation event, with say, a new appendage or firmly distinct morphology in the very short time that we've been doing DNA-based science?

For that matter, is a chicken still viable with the wild species we chose in order to breed, well, chickens?

Probably stupid questions, since we only have hundreds, or maybe thousands, of years of artifical selection with which to try to radiate/change species in the same manner that 3.8 Billion years has, naturally.

I realize the real problem here is the question of 'species' since we define it in so many ways. Have we ever created 'strands' (for want of a better word) of drosophila which, for whatever reason (environment, etc.) would never mate with other drosophila?

well we certainly produce genetic mutants ( eg flies or mice) that are infertile or unable to mate but that is not what you are really asking I think. I suspect the answer is we have not been around for nearly long enough to produce a speciation event in terms of the way you describe it. All we can say from observation is it has happened in the past, though retrospectively trying to determine when the exact event occurred is almost impossible.

You are correct that there is a fuzzy definition of species which makes it difficult to give examples that everyone would accept. There have been quite a lot of experiments that produced reproductive isolation (ie. arguably distinct species under the biological species concept) between lines of fruitflies. Some background here.

https://en.wikipedia.org/wiki/Speciation

I don't know this literature well but I think the claim of speciation has been disputed in at least some of the cases.