DISSERTATION RESEARCH: Consequences of adaptive behavioral plasticity for selection on an acoustic signal

进化生物学的一个中心问题是理解当种群处于选择状态时，性状表达的灵活性（称为可塑性）是如何发挥作用的：灵活性是促进还是阻碍进化？灵活性可以通过创造新的性状来促进进化，选择可以对这些性状起作用;或者，灵活性可以通过保护有害性状的基因不被选择来阻碍进化。交配行为的灵活性可能特别重要，因为它可以允许维持小的或孤立的种群，其中首选类型的可用配偶很少，或者在种群分化中发挥作用，最终导致一个物种分化为两个或更多个。这个项目通过研究配偶偏好的灵活性如何影响求爱的进化来解决这个基本问题。在这个项目中，一名研究生和一名本科生将获得行为生态学和生物声学方面的综合研究经验。此外，研究人员将通过动手科学活动，公开露面和为非技术观众写作，针对小学生，非科学职业的成年人和科学代表性不足的群体的成员进行科学教育和推广活动。该项目研究了在发展过程中雄性歌曲质量的经验如何影响太平洋田野蟋蟀的雌性交配行为。雄性蟋蟀发出歌声，雌性蟋蟀用歌声来识别和定位合适的配偶。在夏威夷，蟋蟀经历了一个新的选择压力，对唱歌的首选歌曲：一个声学定向寄生蝇，优先侵扰男性与女性蟋蟀喜欢的相同的歌曲特征。最近，出现了一种突变，使雄性蟋蟀强制性沉默（“平翅”）。雌蟋蟀强烈喜欢唱歌的男性，也有方向偏好的时间属性的歌曲。可塑性表达这些偏好可以促进维护这个人口时，可用的男性首选的表型很少，但这种可塑性可能会产生后果的强度选择性信号。事实上，雄性和雌性都在沉默中长大，模仿全突变的环境，变得更趋声，这表明交配行为是可塑的，自然界中对信号的选择可能是放松的。在这项研究中，研究人员将在声学环境中饲养蟋蟀，这些声学环境根据偏好特征的值而变化，并使用趋声性试验（雌性）和歌曲录音（雄性）来确定：1）信号产生是否具有可塑性; 2）雌性交配偏好的表达是否具有可塑性; 3）这种可塑性程度的群体差异是否支持交配行为的可塑性是平翅引入后的适应性反应的假设。

A central problem in evolutionary biology is understanding how flexibility (termed plasticity) in the expression of traits functions when populations are under selection: does flexibility facilitate or hamper evolution? Flexibility could facilitate evolution by creating new traits on which selection could act; alternatively, flexibility could hamper evolution by protecting genes for detrimental traits from being selected. Flexibility in mating behavior can be especially important because it could allow the maintenance of small or isolated populations, where available mates of preferred types are few, or play a role in the divergence of populations, ultimately leading to divergence of one species into two or more. This project addresses this fundamental question by examining how flexibility in mate preference could affect the evolution of courtship. During this project, a graduate student and an undergraduate participant will gain comprehensive research experience in behavioral ecology and bioacoustics. In addition, the researchers will engage in science education and outreach activities aimed at elementary school children, adults in non-science careers, and members of underrepresented groups in science via hands-on science activities, public appearances, and writing for non-technical audiences.This project examines how the experience of male song quality during development affects female mating behavior in the Pacific field cricket. Male crickets produce song that females use to identify and localize appropriate mates. Within Hawaii, the crickets experience a novel selection pressure against singing preferred songs: an acoustically orienting parasitoid fly that preferentially infests males with the same song characteristics preferred by female crickets. Recently, a mutation arose that makes male crickets obligately silent ('flatwing'). Female crickets strongly prefer singing males, and also have directional preferences about temporal properties of the song. Plasticity in expression of these preferences could facilitate maintenance of this population when available males of preferred phenotypes are few, but this plasticity could have consequences for the strength of selection on sexual signals. Indeed, both males and females reared in silence, mimicking an all-mutant environment, become more phonotactic, suggesting that mating behavior is plastic and selection on signals in nature may be relaxed. In this study, the researchers will rear crickets in acoustic environments that vary by the value of a preferred trait and use phonotaxis trials (females) and song recordings (males) to determine: 1) whether signal production is plastic; 2) whether expression of female mating preferences is plastic; 3) whether population differences in the extent of this plasticity support the hypothesis that plasticity in mating behavior is an adaptive response following the introduction of flatwing.