Jonathan Wells' objections to evolution are well-known around here, and they're not very sound. He basically says what evolutionary biologists have long known, which is that homology, while providing clues to evolutionary links between animals, are not 100% reliable. Genetic similarities provide much more quantitative information as to the common descent of organisms, and confirm the genetic relations that were long suspected by evolutionary biologists prior to the advent of DNA analysis.
Dr. Wells got himself a PhD, I give him credit for that; but if has anything substantial to say on the subject, he should be submitting for review to legitimate science journals, not posting it directly on the web and direct-to-consumer books. Circumvention of the peer review process is a sure sign of a scientific hack.
A peer review by a community of experts in the relevant field is beneficial but not necessarily a valid test for truth or validity.
There have been studies/articles/theories/books which have been peer reviewed by a community of experts in the relevant field which are/turn out to be invalid.
There have been studies/articles/theories/books which have not been peer reviewed by a community of experts in the relevant field which are/turn out to be valid
The same can be said for a PhD. A PhD is a beneficial academic pursuit but not necessarily a valid test for truth or validity for everything that particular PhD says or writes.