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The evolutionary genetics of paternal care: how good genes and extra-pair copulation affect the trade-off between paternal care and mating success

Citation

Fitzpatrick, Courtney; Ciresi, Colette; Wade, Michael (2021), The evolutionary genetics of paternal care: how good genes and extra-pair copulation affect the trade-off between paternal care and mating success, Dryad, Dataset, https://doi.org/10.5061/dryad.xwdbrv1c8

Abstract

We investigate the evolution of a gene for paternal care, with pleiotropic effects on male mating fitness and offspring viability, with and without extra pair copulations (EPCs). We develop a population genetic model to examine how pleiotropic effects of a male mating advantage and paternal care are affected by ‘good genes’ and EPCs. Using this approach, we show that the relative effects of each on fitness do not always predict the evolutionary change. We then find the line of combinations of mating success and paternal care that bisects the plane of possible values into regions of positive or negative gene frequency change. This line shifts when either good genes or EPCs are introduced, thereby expanding or contracting the region of positive gene frequency change and significantly affecting the evolution of paternal care. Predictably, a direct viability effect of ‘good genes’ that enhances offspring viability constrains or expands the parameter space over which paternal care can evolve, depending on whether the viability effect is associated with the paternal care allele or not. In either case, the effect of a ‘good gene’ that enhances offspring viability is substantial; when strong enough, it can even facilitate the evolution of poorpaternal care, where males harm their young. When non-random mating is followed by random EPCs, the genetic regression between sire and offspring is reduced and, consequently, the relative strengths of selection are skewed away from paternal care and toward the male mating advantage. However, when random mating is followed by non-random EPCs, a situation called “trading up” by females, we show that selection is skewed in the opposite direction, away from male mating advantage and toward paternal care across the natural range of EPC frequencies.

Methods

No empirical data. These files are mathematica notebooks which are used to solve equations and to generate simulations. 

Usage Notes

All files are legible and excecutable in Wolfram Mathematica, and include annotation. 

Funding

National Institutes of Health, Award: 5T32HD049336-12

John Templeton Foundation

Wissenschafts Kollege zu Berlin