Varied female and male courtship behavior facilitated the evolution of a novel sexual signal
Varied female and male courtship behavior facilitated the evolution of a novel sexual signal
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DOI：
10.1093/beheco/arac049
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发表时间：
2022-06-08
影响因子：
2.4
通讯作者：
Tinghitella, Robin M.
中科院分区：
文献类型：
--
作者：
Fitzgerald, Sophia L.;Anner, Sophia C.;Tinghitella, Robin M.
当择偶过程中表达的信号和偏好在群体内耦合，但在群体之间却有所不同（产生选型交配）时，性选择可能有助于物种形成。当新的性信号出现时，研究它们在交配地点和求爱环境中的作用非常重要，因为这两种信号功能在择偶过程中都至关重要。在之前的工作中，研究人员在太平洋田蟋蟀（Teleogryllus oceanicus）的夏威夷种群中发现了两种新的雄性变体（沉默的和发出咕噜声的）。这些变体的进化可能是因为它们保护雄性免受声学定向寄生蜂的侵害，但仍然获得了一些繁殖成功。但是，目前还不清楚这种咕噜声变体在近距离求偶中如何发挥作用。我们将最近进化的咕噜变种与祖先和沉默变种在求爱过程中的相对成功进行了比较。发出呼噜声的雄性会发出一种新颖的求爱歌曲，并且在求爱方面不像祖先类型那么成功，但与20年前出现和传播的专性沉默变体一样频繁和迅速地被雌性骑上。发出咕噜声的雄性比其他变体更快地开始求爱，而来自经常发出咕噜声的种群的雌性则表现出更高的总体爬升率。因此，在发出咕噜声的人群中，雄性和雌性的行为差异可能促进了这种新颖的性信号的起源。我们发现给定形态的雄性和来自其自身种群的雌性之间没有选型交配，因此我们假设该物种内将维持多种雄性类型，因为每种雄性类型以不同的方式实现适应性。
Sexual selection can contribute to speciation when signals and preferences expressed during mate choice are coupled within groups, but come to differ across groups (generating assortative mating). When new sexual signals evolve, it is important to investigate their roles in both mate location and courtship contexts, as both signaling functions are critical in mate choice. In previous work, researchers identified two new male morphs (silent and purring) in Hawaiian populations of the Pacific field cricket, Teleogryllus oceanicus. These morphs likely evolved because they protect males from an acoustically orienting parasitoid, yet still obtain some reproductive success. But, it remains unknown how the purring morph functions in close courtship encounters. We compared the relative success of the very recently evolved purring morph to that of the ancestral and silent morphs during courtship encounters. Purring males produce a novel courtship song and were not as successful in courtship as the ancestral type, but were mounted by females as often and as quickly as the obligately silent morph that arose and spread similar to 20 years ago. Purring males initiate courtship more quickly than other morphs, and females from populations where purring is common exhibit higher overall mounting rates. Thus, differences in the behavior of purring males and of females from populations where purring is common may have facilitated the origin of this novel sexual signal. We found no assortative mating between males of a given morph and females from their own population, and so we hypothesize that multiple male types will be maintained within the species because each achieves fitness in different ways.