Data from: Evolution of pre-copulatory and post-copulatory strategies of inbreeding avoidance and associated polyandry

Inbreeding depression is widely hypothesised to drive adaptive evolution of pre-copulatory and post-copulatory mechanisms of inbreeding avoidance, which in turn are hypothesised to affect evolution of polyandry (i.e., female multiple mating). However, surprisingly little theory or modelling critically examines selection for pre-copulatory or post-copulatory inbreeding avoidance, or both strategies, given evolutionary constraints and direct costs, or examines how evolution of inbreeding avoidance strategies might feed back to affect evolution of polyandry. Selection for post-copulatory inbreeding avoidance, but not for pre-copulatory inbreeding avoidance, requires polyandry, while interactions between pre-copulatory and post-copulatory inbreeding avoidance might cause functional redundancy (i.e., `degeneracy') potentially generating complex evolutionary dynamics among inbreeding strategies and polyandry. We used individual-based modelling to quantify evolution of interacting pre-copulatory and post-copulatory inbreeding avoidance and associated polyandry given strong inbreeding depression and different evolutionary constraints and direct costs. We found that evolution of post-copulatory inbreeding avoidance increased selection for initially rare polyandry, and that evolution of a costly inbreeding avoidance strategy became negligible over time given a lower cost alternative strategy. Further, fixed pre-copulatory inbreeding avoidance often completely precluded evolution of polyandry and hence post-copulatory inbreeding avoidance, but fixed post-copulatory inbreeding avoidance did not preclude evolution of pre-copulatory inbreeding avoidance. Evolution of inbreeding avoidance phenotypes and associated polyandry are therefore affected by evolutionary feedbacks and degeneracy. All else being equal, evolution of pre-copulatory inbreeding avoidance and resulting low polyandry is more likely when post-copulatory inbreeding avoidance is precluded or costly, and evolution of post-copulatory inbreeding avoidance greatly facilitates evolution of costly polyandry.近交衰退（inbreeding depression）被广泛假设为驱动交配前与交配后近交回避机制适应性进化的核心因素，而这些机制反过来又被认为会影响一妻多夫制（即雌性多次交配）的进化。然而，令人惊讶的是，鲜有理论或模型会在考虑进化约束与直接成本的前提下，批判性地检验针对交配前、交配后近交回避，或同时针对这两种策略的选择压力；亦鲜有研究探讨近交回避策略的进化如何反过来影响一妻多夫制的进化。针对交配后近交回避的选择压力需要以一妻多夫制为前提，而针对交配前近交回避的选择压力则无此要求；同时，交配前与交配后近交回避之间的相互作用可能产生功能冗余（即"简并性"），进而在近交策略与一妻多夫制之间催生复杂的进化动力学。我们采用基于个体的建模（individual-based modelling）方法，量化了在强近交衰退、不同进化约束与直接成本条件下，相互关联的交配前与交配后近交回避以及相关一妻多夫制的进化过程。研究结果显示，交配后近交回避的进化会增强对原本稀有一妻多夫制的选择压力；而当存在低成本替代策略时，高成本近交回避策略的进化优势会随时间推移逐渐消失。此外，固定的交配前近交回避通常会完全阻碍一妻多夫制乃至交配后近交回避的进化，但固定的交配后近交回避却不会阻碍交配前近交回避的进化。由此可见，近交回避表型及其相关一妻多夫制的进化，会受到进化反馈与简并性的影响。在其他条件一致的情况下，当交配后近交回避受到限制或成本高昂时，交配前近交回避的进化以及由此产生的低一妻多夫制会更易发生；而交配后近交回避的进化则会极大地促进高成本一妻多夫制的进化。