[
Nature,
1999]
Animal evolution is commonly viewed as producing diverse, environmentally adapted bodies to propagate the germ line. The evolutionary theory of ageing suggests that genetic limits to lifespan may be inadvertent consequences of evolutionary selection for maximizing that propagation. In other words, trade-offs occur that favour reproductive success over post-reproductive longevity; lifespan should be inversely correlated with fecundity when progeny production diverts resources from the maintenance of somatic (non-reproductive) cells. The germ line contains all the genetic information to specify the soma. But it is also possible that there are other, environmentally modulated instructions for life history that the germ line conveys to the soma to maximize reproduction.