Collaborative Research: From Exaptation to Key Innovation - Evolutionary Insights from Gliding Geckos

物种的性状进化为一种功能，但后来被进化修改为一种新的功能，被称为外适应。虽然有许多这样的特征的例子，但它们进化的过程仍然知之甚少。该项目将推进我们对进化如何重塑物种特征的遗传蓝图以创造新的，新颖的创新的理解。与滑翔和飞行有关的特征，如羽毛，是一些最显著的适应性外化的例子。不幸的是，大多数滑翔物种已经高度专业化，很难研究发生适应的过程。壁虎，这是这个研究项目的重点，是一个例外。壁虎已经从用于伪装的皮瓣中多次进化出滑翔结构，并且有多个物种共同代表了从一般到高度专业化滑翔能力的完整过渡。这些进化复制使研究人员能够测试特定特征的适应是否遵循可预测的模式，并提供了一种测量形式和功能如何相互作用以影响进化速度的方法。这项研究将为本科生、研究生和博士后提供遗传学、形态学、生物信息学和图像分析方法的研究培训。公众也将通过在山姆诺布尔博物馆开发一个教育项目来参与，该项目将提供与壁虎滑翔相关的适龄信息和学习活动。这项研究将确定壁虎在进化关系背景下与滑翔相关的适应性增强的后果。将解决两个主要的研究问题：（1）滑动结构是否代表以可预测的方式进化的外适应，以及（2）这些特征或相关的功能转变是否代表导致受影响分支进化速率转变的关键创新。PI将通过结合现场，实验室和计算方法来解决这些问题。完全解决进化树将估计滑翔壁虎和相关的血统。滑动和非滑动壁虎的结构变化将使用外部观察，diceCT和组织学的组合进行调查。滑翔类群之间的发育相似性将通过分析胚胎形态和发育基因表达模式在一组范例类群进行评估。相对隐蔽和滑翔性能值将通过观察活体动物和模型实验来测量，以记录从伪装到滑翔的功能转变。系统发育比较分析将被用来确定模式的表型和谱系多样化及其关系的形态和功能的变化，在这个组。将产生大量新的DNA序列数据;形态数据，包括许多全身CT扫描;以及性能数据，这些数据将引起科学界的广泛兴趣和使用。

Traits of species that evolved to serve one function but were later modified by evolution to serve a new function are known as exaptations. While there are many examples of such traits, the process by which they evolve is still poorly understood. This project will advance our understanding of how evolution reshapes the genetic blueprint of species traits to create new, novel innovations. Traits associated with gliding and flying, like feathers, are some of the most notable examples of exaptations. Unfortunately, most gliding species are already highly specialized, making it difficult to study the process by which exaptation has occurred. Geckos, which are the focus of this research project, are an exception. Geckos have evolved gliding structures multiple times from flaps of skin used in camouflage and there are multiple species that together represent the complete transition from general to highly specialized gliding ability. These evolutionary replicates allow the researchers to test whether exaptation of particular traits follows predictable patterns and also provide a means of measuring how form and function interact to affect rates of evolution. This research will provide research training to undergraduates, graduate students, and a postdoc in genetic, morphological, bioinformatic, and image analysis methods. The public also will be engaged by developing an educational program at the Sam Noble Museum that will feature age-appropriate information and learning activities related to gliding in geckos.This research will determine the consequences of gliding-associated exaptations of geckos within a context of evolutionary relationships. Two primary research questions will be addressed: (1) whether gliding structures represent exaptations that evolve in a predictable way, and (2) whether these traits or the associated functional shift represent key innovations leading to shifts in the rate of evolution in the affected clades. The PIs will address these questions by combining field, laboratory, and computational approaches. Fully resolved evolutionary trees will be estimated for gliding geckos and related lineages. Structural variation in gliding and non-gliding geckos will be surveyed using a combination of external observation, diceCT, and histology. Developmental similarities among gliding taxa will be assessed by analyzing embryonic morphology and developmental gene expression patterns in a set of exemplar taxa. Relative cryptic and gliding performance values will be measured by both observing live animals and by experimenting with models to document the functional shift from camouflage to gliding. Phylogenetic comparative analyses will be employed to identify patterns of phenotypic and lineage diversification and their relationships to morphological and functional change in this group. A significant volume of new DNA sequence data; morphological data, including numerous full-body CT scans; and performance data will be produced and be of broad interest and use to the scientific community.