Don Ewert is a standard creationist talking head and oft-quoted “expert” on subjects related to evolution insofar as he does appear to have a Ph.D. in Microbiology from the University of Georgia. Indeed, Ewert used to operate a research laboratory at the Wistar Institute, and has in fact coauthored some publications in not entirely unrelated fields back in the days – though even his coauthors deny that the publications show what Ewert really wants them to have shown. Given his qualifications Ewert is a signatory to the Discovery Institute’s A Scientific Dissent From Darwinism, and he was called to testify before the Texas Board of Education during their 2009 evolution hearings.
Currently he precheas creationism to anyone who can be bothered to listen, as well as defending the Discovery Institute’s Orwellian take on Academic Freedom before various school boards and legislative bodies, and lamenting the outcome of the Dover case. You can read a summary of his presentation “Comparative Immunology and the Quest to Understand our Origins” here. Short version: the immune system couldn’t have evolved, and to prove it Ewert quotemines some papers, though none that are less than 20 years old (there is a good resource on creationists take on the immune system here). He is not a physicist either, as evidenced by this quote.
Admittedly, Ewert is really just one of many minor opponents of science and reason when science and reason conflict with religion. Among Baptist creationists in particular, we also need to mention Wade Warren, described here.