Daniel Engber has written a provocative article for Slate that challenges the usefulness of the ubiquitous mouse model:

That is to say, we’ve arrived at something like a monoculture in biomedicine. The great majority of how we understand disease, and attempt to cure it, derives from a couple of rodents, selected—for reasons that can seem somewhat arbitrary in retrospect—from all the thousands of other mammals, tens of thousands of other vertebrates, and millions of other animal species known to walk or swim or slither the Earth. We’ve taken the mouse and the rat out of their more natural habitats, from fields and barns and sewers, and refashioned them into the ultimate proxy for ourselves—a creature tailored to, and tailored by, the university basement and the corporate research park.