Interactions among mechanisms of sexual selection on male body size and head shape in a sexually dimorphic fly
Interactions among mechanisms of sexual selection on male body size and head shape in a sexually dimorphic fly
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DOI：
10.1111/j.0014-3820.2003.tb00384.x
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发表时间：
2003-09-01
期刊：
影响因子：
3.3
通讯作者：
Rowe, L
中科院分区：
文献类型：
--
作者：
Bonduriansky, R;Rowe, L
达尔文认为，雄性与雄性、雄性与雌性之间的相互作用是性选择的相互支持机制，在这种机制中，武装最好的雄性对雌性也最有吸引力。虽然这种信念今天仍然占主导地位，但它受到了性冲突理论的挑战，该理论认为男性和女性利益的分歧可能导致冲突的性选择。这就提出了一个经验问题，即性选择的多种机制如何相互作用以塑造目标性状。我们调查了性选择的男性形态的性二态性苍蝇Prochyliza xanthostoma，在实验室舞台上的男性-男性和男性-女性的相互作用中的男性性能的指数，计算梯度的直接，线性选择男性的身体大小和头部伸长的指数。在男性对男性的战斗中，与新对手的第一次互动选择了大的身体尺寸，但减少了头部伸长，而与同一个对手的多次互动只有利于大的身体尺寸。在男女互动中，女性更喜欢头部相对较长的男性，但男性的precopulatory飞跃的表现有利于大的身体尺寸，并可能减少头部伸长。此外，转移的精子数量（其中大部分被雌性摄入）是身体大小和头部伸长的增加函数。因此，虽然男性与男性和男性与女性的相互作用有利于男性的身体尺寸大，男性的头部形状似乎受到冲突的性选择。我们认为，冲突的性选择可能是一个共同的结果分歧的利益的性别。
Darwin envisaged male-male and male-female interactions as mutually supporting mechanisms of sexual selection, in which the best armed males were also the most attractive to females. Although this belief continues to predominate today, it has been challenged by sexual conflict theory, which suggests that divergence in the interests of males and females may result in conflicting sexual selection. This raises the empirical question of how multiple mechanisms of sexual selection interact to shape targeted traits. We investigated sexual selection on male morphology in the sexually dimorphic fly Prochyliza xanthostoma, using indices of male performance in male-male and male-female interactions in laboratory arenas to calculate gradients of direct, linear selection on male body size and an index of head elongation. In male-male combat, the first interaction with a new opponent selected for large body size but reduced head elongation, whereas multiple interactions with the same opponent favored large body size only. In male-female interactions, females preferred males with relatively elongated heads, but male performance of the precopulatory leap favored large body size and, possibly, reduced head elongation. In addition, the amount of sperm transferred (much of which is ingested by females) was an increasing function of both body size and head elongation. Thus, whereas both male-male and male-female interactions favored large male body size, male head shape appeared to be subject to conflicting sexual selection. We argue that conflicting sexual selection may be a common result of divergence in the interests of the sexes.