A general model for selection among modules in haplo-diploid life histories

Generic variation resulting from changes during somatic development in modu lar organisms may be inherited by subsequent generations due to the late de velopment of their germ line. As a consequence, both sexually and asexually produced offspring may be genetically variable. The presence of heritable intraclonal variation and the great life history variation among modular or ganisms requires that evolutionary theory does not limit selection to only that occurring among individuals resulting from meiosis and zygote formatio n. To allow for variation within clonal lineages, and encompass a wide vari ety of life histories, we construct a simple model of selection among modul es in life histories that contain both haploid slid diploid phases, such as that seen among many multicellular algae. Selection among modules is a dem ographic process with module performance depending on its genotype at a sin gle locus with two alleles. The model is used to simulate the spread of a b eneficial allele in life histories that vary in the relative amount of sexu al and asexual reproduction. The time taken for allele fixation is shown to depend on both demographic and genetic factors.