This analysis is highly prejudiced, as a for instance.
Look at 5.3.1
Drosophila paulistorum
The writer objects that
Boxhorn is saying that two fruit flies which he asserts are different species, successfully mate and produce offspring (thereby proving conclusively that they are not different species but the same species.)
He appears to have entirely missed the key point that " In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains
produced only sterile males." the emphasis is mine. This is clearly exactly the sort of physiological isolation he has been banging on about and it arose at some point between 1958 and 1963, the fact that it occurs in the offspring of the crosses rather than occuring during the fertilisation/ development of the embryo is irrelevant, it may be long after mating has ocurred but if you can only produce sterile males then you clearly aren't a viable interbreeding population. Being able to produce offspring isn't the vital criteria, its being able to produce offspring which can go on to breed.
The article casts no doubt on evolution, all it does is object to the 'weak' definition of species. It gives no evidence that post-mating isolation cannot arise from pre-mating isolation and overlooks examples where post-mating isolation, which would qualify for the strong definition, is clearly in evidence.
TTFN,
WK