title: Pattern and paradox in parasite reproduction.
abstract: Parasites are more fecund than free-living relatives. The traditional explanation of this is that parasites have to compensate for massive mortality in the transmission phase of their life cycles, but there are neo-Darwinian problems with this interpretation. Similarly, parasites invest more resources in reproduction than free-living relatives but often live longer as adults, and yet negative correlations are expected between fecundity and longevity. These patterns and paradoxes are discussed within the context of a general life-cycle theory. The theory is also used to address questions concerning the influence of age-specific mortality on life-cycle patterns, the trade-off between gamete size and numbers, and the relative merits of gametic and non-gametic reproduction. Wherever possible, the theory is related to facts about parasites.
mesh_terms: D000818:Animals; D002589:Cestoda / Q000502:physiology; D056890:Eukaryota / Q000502:physiology; D005260:Female; D005298:Fertility; D006790:Host-Parasite Interactions; D008136:Longevity; D008297:Male; D008433:Mathematics; D008954:Models, Biological; D010271:Parasites / Q000502:physiology*; D012098:Reproduction; D012100:Reproduction, Asexual; D014200:Trematoda / Q000502:physiology