Polyandry is often hypothesized to evolve to allow females to adjust the degree to which they inbreed. Multiple factors might affect such evolution, including inbreeding depression, direct costs, constraints on male availability, and the nature of polyandry as a threshold trait. Complex models are required to evaluate when evolution of polyandry to adjust inbreeding is predicted to arise. We used a genetically explicit individual-based model to track the joint evolution of inbreeding strategy and polyandry defined as a polygenic threshold trait. Evolution of polyandry to avoid inbreeding only occurred given strong inbreeding depression, low direct costs, and severe restrictions on initial versus additional male availability. Evolution of polyandry to prefer inbreeding only occurred given zero inbreeding depression and direct costs, and given similarly severe restrictions on male availability. However, due to its threshold nature, phenotypic polyandry was frequently expressed even when strongly selected against and hence maladaptive. Further, the degree to which females adjusted inbreeding through polyandry was typically very small, and often reflected constraints on male availability rather than adaptive reproductive strategy. Evolution of polyandry solely to adjust inbreeding might consequently be highly restricted in nature, and such evolution cannot necessarily be directly inferred from observed magnitudes of inbreeding adjustment.
PolyInbreeding_Code.tar: This compressed directory contains the 45 files needed to compile the code underlying the paper and run all simulations. Parameter values for simulations are set in the PolyIn.c file, which by default outputs three separate TXT files. The output files can be used in the PolyInbreeding_Analysis.R file to recreate all analyses and figures from the paper. This code is also publicly available, with additional documentation, on Brad Duthie's GitHub repository: https://github.com/bradduthie/PolyInbreed
This work is licensed under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication license.
- Inbreeding preference
- Inbreeding strategy
- Mate choice
- multiple mating