Delayed prezygotic isolating mechanisms: evolution with a twist.

摘要: Assortative mating characterizes the situation wherein reproducing individuals pair according to similarity. Usually, impetus for this bias is attributed some type of mate choice conferring benefits (e.g., increased fitness or genetic compatibility) and, thereby, promoting speciation and phenotypic evolution. We investigate, by computer simulation an evolving deme-structured snail population, ramifications ensuing from passive assortative couples exhibiting opposite shell coil direction phenotypes experience a physical constraint on success: putative partners inhabiting stout dextral sinistral shells are unable exchange sperm. Because chirality genotype encoded at single locus alleles that inherited maternally, snails containing can present typical phenotype. Consequently, incidence allele in as few one be manifested prezygotic reproductive isolation within deme subsequent generation. However, because efficacy achieving affected form, likelihood product single-gene should determined interaction (migration) composition (morphological distribution). test hypothesis show how stochastic migration interacts with yielding morphologically induced produce new species phenotypes. The results demes achieve rapid macroscopic transformation indicate sympatric might more plausible than naturalists recognize conventionally.