Prevalence of loss-of-function alleles does not correlate with lifetime fecundity and other life-history traits in metazoans

Abstract

Natural selection is possible only because all species produce more offspring than what is needed to maintain the population. Still, the lifetime number of offspring varies widely across species. One can expect natural selection to be stronger in high-fecundity species. We analyzed the prevalence of loss-of-function alleles in 32 metazoan species and have found that, in contrast to this expectation, the strength of negative selection does not correlate with lifetime fecundity, as well as with other life-history traits. Perhaps, higher random mortality in high-fecundity species negates the effect of increased opportunity for selection.