Multiple sexual selection pressures drive the rapid evolution of complex morphology in a male secondary genital structure
Multiple sexual selection pressures drive the rapid evolution of complex morphology in a male secondary genital structure
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DOI：
10.1002/ece3.1721
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发表时间：
2015-10-01
影响因子：
2.6
通讯作者：
Masly, John P.
中科院分区：
文献类型：
--
作者：
Frazee, Stephen R.;Masly, John P.
内生类的外生殖器是快速形态进化的一个显著例子。虽然性选择可以塑造生殖器形态的变化，但很难测试多重性选择压力是否结合联合收割机来驱动个体生殖器结构的快速进化。在这里，我们测试的假设，前和交配后的性选择可以采取一致行动，以形成复杂的结构变化，次级生殖器形态。我们对果蝇雄性后叶的大小和形状进行了遗传修饰，并测试了形态变异对几种生殖措施的影响。我们发现，后叶是必要的生殖器耦合，他们也是目标的多个postcopulatory过程，形状的形态定量变化，即使这些结构没有直接接触的外部女性生殖器或内部生殖器官在交配。我们还发现，男性较小，结构不太复杂的后叶遭受大量的健身成本在竞争性受精实验。我们的研究结果表明，性选择机制可以联合收割机，形成一个单一的生殖器结构的形态和后叶的D.melanogaster是多个交配后选择压力的目标。
The genitalia of internally fertilizing taxa represent a striking example of rapid morphological evolution. Although sexual selection can shape variation in genital morphology, it has been difficult to test whether multiple sexual selection pressures combine to drive the rapid evolution of individual genital structures. Here, we test the hypothesis that both pre- and postcopulatory sexual selection can act in concert to shape complex structural variation in secondary genital morphology. We genetically modified the size and shape of the posterior lobes of Drosophila melanogaster males and tested the consequences of morphological variation on several reproductive measures. We found that the posterior lobes are necessary for genital coupling and that they are also the targets of multiple postcopulatory processes that shape quantitative variation in morphology, even though these structures make no direct contact with the external female genitalia or internal reproductive organs during mating. We also found that males with smaller and less structurally complex posterior lobes suffer substantial fitness costs in competitive fertilization experiments. Our results show that sexual selection mechanisms can combine to shape the morphology of a single genital structure and that the posterior lobes of D.melanogaster are the targets of multiple postcopulatory selection pressures.