LIFESPAN AND BREEDING. “A longer lifespan normally implies increased reproductive success, and factors such as low adult mortality (permitting more reproductive events per lifetime), high juvenile mortality (making it necessary for adults to reproductively compensate for such loss), and high variation in juvenile mortality from one bout of reproduction to the next (increasing uncertainty in reproductive success and requiring reproductive compensation as well) therefore all tend to lengthen reproductive lifespan.”
http://www.nature.com/scitable/knowledge/library/the-evolution-of-aging-23651151
