Data from: Population demography and heterozygosity-fitness correlations in natural guppy populations: an examination using sexually selected fitness traits

Heterozygosity-fitness correlations (HFCs) have been examined in a wide diversity of contexts, and the results are often used to infer the role of inbreeding in natural populations. Although population demography, reflected in population-level genetic parameters such as allelic diversity or identity disequilibrium, is expected to play a role in the emergence and detectability of HFCs, direct comparisons of variation in HFCs across many populations of the same species, with different genetic histories, are rare. Here, we examined the relationship between individual microsatellite heterozygosity and a range of sexually selected traits in 660 male guppies from 22 natural populations in Trinidad. Similar to previous studies, observed HFCs were weak overall. However, variation in HFCs among populations was high for some traits (although these variances were not statistically different from zero). Population-level genetic parameters, specifically genetic diversity levels (number of alleles, observed/expected heterozygosity) and measures of identity disequilibrium (g2 and heterozygosity-heterozygosity correlations) were not associated with variation in population-level HFCs. This latter result indicates that these metrics do not necessarily provide a reliable predictor of HFC effect sizes across populations. Importantly, diversity and identity disequilibrium statistics were not correlated, providing empirical evidence that these metrics capture different essential characteristics of populations. A complex genetic architecture likely underpins multiple fitness traits, including those associated with male fitness, which may have reduced our ability to detect HFCs in guppy populations. Further advances in this field would benefit from additional research to determine the demographic contexts in which HFCs are most likely to occur.杂合度-适合度相关性（Heterozygosity-fitness correlations, HFCs）已在多样化的研究情境中得到广泛考察，其结果常被用于推断近交在自然种群中的作用。尽管种群人口统计学特征可通过等位基因多样性、同一性不平衡等种群水平遗传参数体现，且被认为会影响HFCs的产生与可检测性，但针对同一物种不同遗传历史的多个种群间HFC变异的直接比较仍较为少见。本研究以特立尼达22个自然种群的660条雄性孔雀鱼为研究对象，探究了个体微卫星杂合度与一系列性选择性状之间的关联。与既往研究结果相似，本研究观测到的HFCs整体强度较弱。不过，部分性状的种群间HFC变异程度较高（尽管这些变异在统计学上与零无显著差异）。种群水平的遗传参数，具体包括遗传多样性水平（等位基因数量、观测/期望杂合度）以及同一性不平衡度量指标（g2与杂合度-杂合度相关性），与种群水平HFC的变异并无显著关联。这一结果表明，上述度量指标未必能可靠预测不同种群间的HFC效应量。值得注意的是，遗传多样性与同一性不平衡统计量之间不存在相关性，这为二者捕捉种群的不同核心特征提供了实证依据。复杂的遗传结构可能是包括雄性适合度相关性状在内的多种适合度性状的遗传基础，这或许降低了我们在孔雀鱼种群中检测HFCs的能力。该领域的后续研究可聚焦于探索HFCs最易出现的人口统计学背景，以推动相关研究的进一步发展。