Department of Biology, Indiana University Herbarium, Indiana University, Bloomington, IN, USA.
Biol Lett. 2024 Feb;20(2):20230499. doi: 10.1098/rsbl.2023.0499. Epub 2024 Feb 28.
Fitness gain curves were introduced into the framework of the Shaw-Mohler equation, the foundation of sex allocation theory. I return to the Shaw-Mohler equation to consider how it embodies the rare-sex advantage underlying frequency-dependent selection on the sex ratio. The Shaw-Mohler formulation is based on the numbers of males and females randomly mating in a panmictic population. Gain curves are meant to describe reproductive success through male and female functions in hermaphrodites and have been inserted in place of male and female numbers in the Shaw-Mohler equation. In doing so, gain curves bypass consideration of the implicit mating process in the Shaw-Mohler argument and can lead to anomalies like unequal total male and female fitness in a population. If gain curves truly represent fitness gain, equality of total male and female fitness requires a constant sex allocation of equal resource investment into male and female functions. The blurring of input with fitness outcome has led to misinterpretation of what gain curves mean in reproductive ecology. They can describe a particular reproductive ecology, such as diminishing fitness returns on resource investment, but lack causal efficacy with respect to sex allocation.
健身增益曲线被引入了 Shaw-Mohler 方程的框架中，该方程是性别分配理论的基础。我回到 Shaw-Mohler 方程，考虑它如何体现了频率依赖性别比例选择背后的稀有性别优势。Shaw-Mohler 的公式基于在混合种群中随机交配的雄性和雌性数量。增益曲线旨在通过雌雄同体的雄性和雌性函数来描述繁殖成功率，并且已经插入到 Shaw-Mohler 方程中的雄性和雌性数量中。这样，增益曲线绕过了 Shaw-Mohler 论点中隐含的交配过程的考虑，并且可能导致像群体中雄性和雌性总适应度不相等这样的异常现象。如果增益曲线真正代表了适应度增益，那么雄性和雌性总适应度的平等需要对雄性和雌性功能进行平等的资源投入的恒定性别分配。输入与适应度结果的模糊性导致了对生殖生态学中增益曲线含义的误解。它们可以描述特定的生殖生态学，例如资源投资的适应度回报递减，但在性别分配方面缺乏因果效力。
