Doctoral Dissertation Improvement: Are gelada loud calls "sexually-selected signals"?

狮尾猿（学名：Theropithecus gelada）和人类一样，生活在一个非常大的社会群体中，其数量超过1000人。然而，与人类不同的是，狮尾狒狒社会中占主导地位的雄性并不认识周围的其他雄性，即使是他们每天都会遇到的雄性。这就为雄性竞争配偶创造了一套社会和进化上（与健康相关）的重要限制;主要是，如何在进行昂贵的竞争之前评估对手。不使用个体识别进行评估的物种通常使用速记代理;即，有助于确定潜在竞争对手的竞争能力的特定物理特征或其他特征（“信号”）。 虽然灵长类动物身上的这种信号很罕见，但狮尾狒狒社会中异常庞大的群体可能通过一种被称为“性选择”的自然选择形式促进了它们的进化。博士生Marcela Benitez（密歇根大学）在Jacinta Beehner博士的监督下进行的研究将研究生活在埃塞俄比亚西米恩山脉国家公园的雄性狒狒的一个假定信号-一种用于雄性展示的响亮声音（即，“大声呼叫”）。确定大声呼叫是否是进化的信号需要确定以下几点：（1）不同质量的雄性之间存在大声呼叫的差异，（2）雄性可以使用这些呼叫来区分高质量和低质量的雄性，（3）雄性然后根据这些呼叫进行挑战，以及（4）具有高质量呼叫的雄性具有更高的适应性（繁殖成功）。为了解决这些预测，这项跨学科的研究将结合联合收割机的声学，实验，激素和观察分析，对已知的个人，已连续跟踪了过去六年。因此，这项研究代表了理论上被称为“性选择信号”（即，这项研究是一个长期项目的一部分，该项目致力于通过合作研究和教育介绍，在美国和埃塞俄比亚提高保护意识和科学教育，以当地人民和生态游客在埃塞俄比亚。博士生Co-PI是一个代表性不足的科学团体的成员，她将把这项研究纳入她的儿童教育宣传双语网站，促进美国儿童参与科学。

Geladas (Theropithecus gelada), like humans, live in unusually large social groups with numbers that exceed 1000 individuals. Unlike humans, however, the dominant males in gelada society do not recognize other males around them - even males that they encounter on a daily basis. This creates a socially and evolutionarily (fitness-related) significant set of limitations for males competing for mates; mainly, how to assess rivals prior to engaging in costly forms of competition. Species that do not use individual recognition for assessment typically use short-hand proxies; i.e., particular physical features or other characteristics ("signals") which are useful for ascertaining the competitive abilities of potential rivals. Although such signals in primates are rare, the unusually large groups found in gelada society may have favored their evolution through a form of natural selection referred to as "sexual selection."Research by doctoral student Marcela Benitez (University of Michigan), under the supervision of Dr. Jacinta Beehner, will examine one such putative signal for male geladas living in the Simien Mountains National Park, Ethiopia - a loud vocalization used in male displays (i.e., "loud calls"). Establishing whether loud calls are evolved signals requires establishing the following: (1) that variation exists in loud calls across males of different quality, (2) that males can use these calls to distinguish between high and low quality males, (3) that males then base challenges on these calls, and (4) that males with high quality calls have higher fitness (reproductive success). To address these predictions, this interdisciplinary research will combine acoustic, experimental, hormonal, and observational analyses on known individuals that have been followed continuously for the past six years. As such, the research represents one of the most comprehensive studies of what are theoretically termed "sexually-selected signals" (i.e., those evolved through male-male reproductive competition) with potential fitness consequences in a primate.This research is part of a long-term project that is committed to increasing conservation awareness and scientific education, both in the U.S. and in Ethiopia, through collaborative research and educational presentations to local people and eco-tourists in Ethiopia. The doctoral student Co-PI, a member of an underrepresented group in science, will incorporate the research into her bilingual website for childhood educational outreach, promoting engagement with the sciences by US children.