As recently as 2002 programmed aging in mammals was widely thought to be theoretically impossible based on generally accepted concepts regarding the evolution process. However, as described in this article, genetics discoveries, results of selective breeding, and other direct evidence strongly support the idea that aging creates an evolutionary advantage and that therefore complex biological mechanisms evolved that control mammal aging. Like similar life-cycle programs that control reproduction, growth, and menopause the aging program can adjust the aging trait during an individual’s life to compensate for temporary or local changes in external conditions that alter the optimum lifespan for a particular species population. In addition, genetics discoveries strongly support the evolvability concept to the effect that sexually reproducing species can evolve design features that increase their ability to evolve, and that aging is one such feature.