Host-parasite interactions and the evolution of ploidy.

ABSTRACT: Although the majority of animals and plants, including humans, are dominated by the diploid phase of their life cycle, extensive diversity in ploidy level exists among eukaryotes, with some groups being primarily haploid whereas others alternate between haploid and diploid phases. Previous theory has illuminated conditions that favor the evolution of increased or decreased ploidy but has shed little light on which species should be primarily haploid and which primarily diploid. Here, we report a discovery that emerged from host-parasite models in which ploidy levels were allowed to evolve: selection is more likely to favor diploidy in host species and haploidy in parasite species. Essentially, when parasites must evade a host's immune system or defense response, selection favors parasitic

SUBMITTER: Nuismer SL 

PROVIDER: S-EPMC503737 | biostudies-literature | 2004 Jul

REPOSITORIES: biostudies-literature