We investigate the evolution of a gene for paternal care, with pleiotropic effects on male mating fitness and offspring viability, with and without extrapair 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 poor paternal care, where males harm their young. When nonrandom 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 nonrandom 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.

中文翻译：

---

父亲照顾的进化遗传学：良好的基因和配对对如何影响父母照顾与交配成功之间的权衡

我们调查了父本护理基因的进化，对雄性交配适应性和后代生存能力具有多效性作用，带有和不带有配对配对（EPC）。我们开发了一个人口遗传模型，以研究“良好基因”和EPC如何影响男性交配优势和父权照顾的多效性。使用这种方法，我们证明了每种方法对适应性的相对影响并不总是能预测进化变化。然后，我们找到了成功交配和父母关怀相结合的路线，将可能值的平面一分为二，分为正向或负向基因频率变化区域。当引入良好基因或EPC时，这条线会移动，从而扩大或缩小正基因频率变化的区域，并显着影响父系护理的发展。可以预见 增强后代生存力的“良好基因”的直接生存力效应会限制或扩大父权保健可以进化的参数空间，具体取决于生存力效果是否与父权保健等位基因相关。无论哪种情况，增强后代生存力的“良好基因”的作用都是可观的。当足够坚固时，它甚至可以促进父辈照顾不好，男性伤害了他们的年轻人。当非随机交配之后是随机的EPC时，父亲和后代之间的遗传回归会降低，因此，选择的相对优势会偏离父辈的照顾，而趋向于男性交配优势。但是，当随机交配之后是非随机EPC（一种被女性称为“向上交易”的情况）时，我们表明选择朝相反的方向倾斜，远离了男性交配优势，并在EPC频率的自然范围内转向了父权照顾。