The latest SAGE Crossroads article examines the evolution of evolutionary theories of aging: "The leading evolutionary explanation for aging has reached its silver years. Born in the late 1940s, the theory matured in the 1960s and flourished in the following decades, as researchers amassed evidence supporting its predictions. But like many of its contemporaries, the theory now needs to have a little work done. Evolution experts don't envision a makeover, merely a few nips and tucks to explain some vexing results from field studies and mathematical models." Evolutionary theories of aging help to direct research into the biochemical and genetic mechanisms of aging; like the Reliability Theory of aging, they provide a framework and testbed for more detail-oriented theories and examinations.