Data from: Sexual signal loss: the link between behavior and rapid evolutionary dynamics in a field cricket

1. Sexual signals may be acquired or lost over evolutionary time, and are tempered in their exaggeration by natural selection. 2. In the Pacific field cricket, Teleogryllus oceanicus, a mutation (“flatwing”) causing loss of the sexual signal, the song, spread in < 20 generations in two of three Hawaiian islands where the crickets have been introduced. Flatwing (as well as some normal-wing) males behave as satellites, moving towards and settling near calling males to intercept phonotactic females. 3. From 2005-2012, we surveyed crickets and their responses to conspecific song, noting the morph and number of males and females before and after experimental playbacks. The three Hawaiian islands consistently contained different proportions of flatwing crickets, ranging from about 90% of males on Kauai to 50% on Oahu to rare on the Big Island of Hawaii. 4. Flatwing and normal-wing males do not appear to differ in responsiveness to playback, a behavior that should influence the likelihood of a male encountering a phonotactic female. Instead, male and female crickets from populations in which little to no calling song is perceptible during development tended to seek out callers more readily than crickets that developed in noisier environments. Such increased phonotaxis makes females more likely to find either the caller to which they are responding or to encounter a flatwing (or normal male satellite) that has also been attracted to the song. 5. Our evidence suggests that pre-existing behavioral plasticity (manifest as flexible responses to social – particularly acoustic – information in the environment) is associated with the rapid spread of the flatwing trait. Different social environments select for differential success of flatwing or normal-wing males, which in turn alters the social environment itself.

1. 性信号可在进化历程中获得或丢失，且其夸张程度会受到自然选择的约束。
2. 太平洋田野蟋蟀（Teleogryllus oceanicus）中，一种名为“平翅型（flatwing）”的突变会导致其性信号——鸣唱——的丢失，该突变在引入该蟋蟀的三个夏威夷群岛中的两个群岛上，仅用不到20代便完成了扩散。平翅型（以及部分正常翅型（normal-wing））雄性会扮演卫星雄性的角色：移动并停留在鸣唱雄性附近，以拦截具有趋音性（phonotaxis）的雌性。
3. 2005年至2012年间，我们对蟋蟀及其对同种鸣唱的响应开展了调查，记录了实验回放（playback）前后雌雄个体的形态型与数量。三个夏威夷群岛的平翅型蟋蟀占比始终存在差异：考艾岛的雄性平翅型个体占比约90%，瓦胡岛为50%，而夏威夷大岛则极为罕见。
4. 平翅型与正常翅型雄性对回放实验的响应性并无显著差异，而该行为本应影响雄性邂逅趋音性雌性的概率。与之相反，相较于在嘈杂环境中发育的蟋蟀个体，在发育过程中几乎或完全无法感知鸣唱的种群中的雌雄蟋蟀，往往更易主动寻找鸣唱者。这种增强的趋音性会使雌性更易找到其所响应的鸣唱者，或是邂逅同样被鸣唱吸引的平翅型（或正常翅型卫星雄性）个体。
5. 我们的研究证据表明，先天存在的行为可塑性（表现为对环境中社交信息——尤其是声学信息——的灵活响应）与平翅型性状的快速扩散存在关联。不同的社交环境会对平翅型或正常翅型雄性的存活与繁殖成功率产生差异化选择，而这反过来又会改变其所在的社交环境本身。