Have we ever demonstrated that two Drosophila sp. that could initially interbreed (in nature or in labs) lineages evolving through artificial selection (and drift) in labs fail to interbreed either due pre- or post- mating isolation? Or, in other words, have we ever demonstrated that two drosophila lineages evolved to become different species in labs experiments?

If not, have we ever observed some partial reproductive isolation such as inbreeding depression for example?

**Background**

The standard definition of species refers to the concept of [reproductive isolation][2]. If two lineages are found to be reproductively isolated, then we consider these two lineages to belong to different species. My question concerns evolved reproductive isolation in Drosophila sp. following labs due to experimental evolution.


  [1]: http://biology.stackexchange.com/questions/17736/if-evolution-is-true-how-would-you-explain-the-fruit-fly-experimentations
  [2]: http://simple.wikipedia.org/wiki/Reproductive_isolation