Department of Behavioural Ecology, Faculty of Biology, Adam Mickiewicz University in Poznan, Poznan, 61-614, Poland.
Department of Biology, University of Padova, Padova, 35121, Italy.
Evolution. 2021 Dec;75(12):3037-3055. doi: 10.1111/evo.14384. Epub 2021 Nov 13.
Female preferences for male ornamental traits can arise from indirect benefits, such as increased attractiveness or better viability of progeny, but empirical evidence for such benefits is inconsistent. Artificial selection offers a powerful way to investigate indirect effects of male ornaments. Here, we selected for the area of orange spots on male guppies, a trait subject to female preferences in our population, in replicated up- and down-selected lines. We found a significant direct response to selection, and a correlated response in female preferences, with females from down-selected lines showing less interest in more orange males. Nevertheless, up-selected males sired more offspring in direct competition with low-selected males, irrespective of female origin. We did not find a significantly correlated response to selection among any other fitness correlates we measured. Our results imply that female preferences for orange spots can lead to increased reproductive success of their sons, with no effect on general viability of progeny. Furthermore, although we demonstrate that female preferences may evolve via linkage disequilibrium with the preferred trait, the potential for runaway selection by positive feedback may be constrained by the lack of corresponding linkage with male reproductive competitiveness.
女性对雄性装饰性特征的偏好可能源于间接利益，例如增加吸引力或后代更好的生存能力，但这种利益的经验证据并不一致。人工选择提供了一种研究雄性装饰物间接影响的有力方法。在这里，我们在雄性孔雀鱼身上选择了橙色斑点区域，这是我们种群中雌性偏好的特征，在经过重复选择的向上和向下选择的系中进行了选择。我们发现了一个显著的直接选择反应，以及雌性偏好的相关反应，来自向下选择系的雌性对更橙色的雄性表现出较少的兴趣。然而，与低选择的雄性相比，经过向上选择的雄性在直接竞争中使更多的后代受精，而不管雌性的来源如何。我们没有发现我们测量的任何其他适合度相关特征中存在与选择相关的显著反应。我们的研究结果表明，雌性对橙色斑点的偏好可能会导致其儿子的繁殖成功率增加，而对后代的一般生存能力没有影响。此外，尽管我们证明了雌性偏好可能通过与所偏好的特征的连锁不平衡而进化，但正反馈的失控选择的可能性可能受到雄性生殖竞争力缺乏相应连锁的限制。
