Dissertation Research: Phenotypic Plasticity of Jaw and Skull Morphology in the Cichlid Fishes, Geophagus braziliensis and G. steindachneri

表型可塑性是生物体对环境变化的反应。这种可塑性通常具有遗传基础，因此可以影响进化的速度和方向。形态可塑性在脊椎动物中知之甚少。越来越多的证据表明，巴西和G.steindachneri，这代表了慈鲷发育模式的极端。我们的研究旨在回答以下问题：（1）进食开始时的大小对表达的形态可塑性的量有什么影响？(2)是否存在与年龄相关的可塑性差异？(3)诱导的形态差异是否影响与不同饲喂模式相关的日粮的饲喂效率？(4)颌骨和头骨的可塑性是否存在遗传变异？这项研究将超越形态可塑性的描述，它将在发育，遗传，功能和生态环境中研究可塑性。只有通过这种跨学科的方法，才能理解可塑性对进化的影响，以及可塑性本身的进化。8700940 McCume表型可塑性是生物体响应环境变化的某些性状的改变。这种可塑性通常具有遗传基础，因此可以影响进化的速度和方向。形态可塑性在脊椎动物中知之甚少。越来越多的证据表明，慈鲷科鱼类（Geophagus braziliensis和G.steindachneri）的颌骨和头骨形态代表了慈鲷科鱼类发育模式的极端。我们的研究旨在回答以下问题：（1）进食开始时的大小对表达的形态可塑性的量有什么影响？(2)是否存在与年龄相关的可塑性差异？(3)诱导的形态差异是否影响与不同饲喂模式相关的日粮的饲喂效率？(4)颌骨和头骨的可塑性是否存在遗传变异？这项研究将超越形态可塑性的描述，它将在发育，遗传，功能和生态环境中研究可塑性。只有通过这种跨学科的方法，才能理解可塑性对进化的影响，以及可塑性本身的进化。8700999约翰逊发声行为在鸣禽的进化过程中很重要，但很少有研究试图解释形态和遗传多样性的声音信息。这项研究将整合声音，形态和遗传数据的高度多型北美红交嘴鸟（Loxia curvirostra）复杂。这个群体提出了一个未解决的进化悖论：鸟类是游牧的，表明基因流动的速度很高，但在群体内的喙大小，身体大小和羽毛颜色都有极大的多样性。几个可检验的替代假设的性质

Phenotypic plasticity is the modification of some trait of an organism in response to environmental change. Often this plasticity has a genetic basis and as a result can influence the rate and direction of evolution. Morphological plasticity is little known among vertebrates. Increasing evidence indicates braziliensis and G.steindachneri, which represent the extremes of cichlid developmental modes. Our research aims to answer the following questions: (1) What effect does the size at which feeding commences have on the amount of morphological plasticity that is expressed? (2) Are there age-related differences in the amount of plasticity that can be induced? (3) Do induced morphological differences affect feeding efficiency on diets that are associated with different feeding modes? (4) Is there genetic variation for the plasticity of jaw and skull bones? This study will go beyond a description of morphological plasticity; it will examine plasticity in a developmental, genetic, functional, and ecological context. Only through such an interdisciplinary approach can the effect of plasticity on evolution, and the evolution of plasticity, itself, be understood. 8700940 McCume Phenotypic plasticity is the modification of some trait of an organism in response to environmental change. Often this plasticity has a genetic basis and as a result can influence the rate and direction of evolution. Morphological plasticity is little known among vertebrates. Increasing evidence indicates that jaw and skull morphology of cichlid fishes, Geophagus braziliensis and G.steindachneri, which represent the extremes of cichlid developmental modes. Our research aims to answer the following questions: (1) What effect does the size at which feeding commences have on the amount of morphological plasticity that is expressed? (2) Are there age-related differences in the amount of plasticity that can be induced? (3) Do induced morphological differences affect feeding efficiency on diets that are associated with different feeding modes? (4) Is there genetic variation for the plasticity of jaw and skull bones? This study will go beyond a description of morphological plasticity; it will examine plasticity in a developmental, genetic, functional, and ecological context. Only through such an interdisciplinary approach can the effect of plasticity on evolution, and the evolution of plasticity, itself, be understood. 8700999 Johnson Vocal behavior is important in evolutionary processes in songbirds, yet few studies have attempted to explain morphological and genetic diversification in light of vocal information. This research will integrate vocal, morphological, and genetic data in the highly polytypic North American red crossbill (Loxia curvirostra) complex. This group presents an unsolved evolutionary paradox: the birds are nomadic, suggesting a high rate of gene flow, yet there is extreme diversity in bill size, body size, and plumage coloration within the group. Several testable alternative hypotheses regarding the nature