Data from: Estimating selection through male fitness: three complementary methods illuminate the nature and causes of selection on flowering time

Our understanding of selection through male fitness is limited by the resource demands and indirect nature of the best available genetic techniques. Applying complementary, independent approaches to this problem can help clarify evolution through male function. We applied three methods to estimate selection on flowering time through male fitness in experimental populations of the annual plant Brassica rapa: (1) an analysis of mating opportunity based on flower production schedules, (2) genetic paternity analysis, and (3) a novel approach based on principles of experimental evolution. Selection differentials estimated by the first method disagreed with those estimated by the other two, indicating that mating opportunity was not the principal driver of selection on flowering time. The genetic and experimental evolution methods exhibited striking agreement overall, but a slight discrepancy between the two suggested that negative environmental covariance between age at flowering and male fitness may have contributed to phenotypic selection. Together, the three methods enriched our understanding of selection on flowering time, from mating opportunity to phenotypic selection to evolutionary response. The novel experimental evolution method may provide a means of examining selection through male fitness when genetic paternity analysis is not possible.

当前学界对基于雄性适合度的选择的认知，受限于现有最优遗传技术的资源需求与间接性特征。针对该问题采用互补且独立的研究方法，有助于阐明雄性功能介导的演化过程。我们针对一年生植物芸薹（Brassica rapa）的实验种群，采用三种方法评估了基于雄性适合度的开花时间选择：（1）基于开花时序的交配机会分析；（2）遗传父本分析（genetic paternity analysis）；（3）基于实验演化原理的全新研究方法。第一种方法估算得到的选择差（selection differential）与另外两种方法的结果不一致，表明交配机会并非开花时间相关选择的主要驱动因素。遗传父本分析与实验演化方法整体呈现出显著的一致性，但二者间存在的细微差异提示，开花年龄与雄性适合度间的负向环境协方差，可能对表型选择产生了影响。三种方法结合后，深化了我们对开花时间相关选择的认知，覆盖了从交配机会、表型选择到演化响应的全维度。在无法开展遗传父本分析的场景下，这种全新的实验演化方法可为通过雄性适合度评估选择提供可行途径。