Evolutionary theory as a tool for predicting extinction risk

•Specialization is a continuum with most species falling in the middle.•Specialization can affect extinction risk, but is rarely applied to such studies.•We justify the need for comparative integration of this idea in vertebrate species.•We present case studies highlighting how specialization affects vulnerability.•A conceptual framework for quantitatively scoring specialization and/or risk is presented.

Timely and proactive wildlife conservation requires strategies for determining which species are most at the greatest threat of extinction. Here, we suggest that evolutionary theory, particularly the concept of specialization, can be a useful tool to inform such assessments and may greatly aid in our ability to predict the vulnerabilities of species to anthropogenic impacts.