A demographic model explains life-history variation in Arabis fecunda

1. The distinction between semelparity and iteroparity is one of the most fundamental in life-history biology. Despite an abundance of theory proposed to explain the evolution of this dichotomy, few quantitative empirical tests exist. 2. We report here on life-history variation in the perennial herb Arabis fecunda (Brassicaceae), in which differences in the frequency of iteroparity and terminal flowering (facultative semelparity) are expressed among populations. These differences are consistent over time, and a common garden experiment suggested that they may be at least partly genetically based. 3. An analysis of demographic data over a 5-year period from three populations indicated that a simple demographic model of life-history evolution is consistent with life-history variation in this species. Individuals in populations with greater mean adult survival were more likely to express iteroparity than individuals in populations with lower adult survival.