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

物种的特征是为了实现一种功能而进化的，但后来又通过进化而被修改以实现一种新的功能，这种特征被称为外适应。尽管有很多此类特征的例子，但人们对它们进化的过程仍然知之甚少。该项目将增进我们对进化如何重塑物种性状的遗传蓝图以创造新的、新颖的创新的理解。与滑翔和飞行相关的特征，如羽毛，是扩展适应的一些最著名的例子。不幸的是，大多数滑翔物种已经高度专业化，因此很难研究外迁发生的过程。作为本研究项目重点的壁虎是一个例外。壁虎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滑翔能力到高度专业化滑翔能力的完全转变。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率的方法。这项研究将为本科生、研究生和博士后提供遗传、形态学、生物信息学和图像分析方法方面的研究培训。公众还将参与在萨姆·诺布尔博物馆制定一项教育计划，该计划将提供与壁虎滑翔相关的适合年龄的信息和学习活动。这项研究将确定在进化关系背景下壁虎与滑翔相关的适应的后果。将解决两个主要研究问题：（1）滑动结构是否代表以可预测的方式进化的扩展，以及（2）这些特征或相关的功能转变是否代表导致受影响进化枝进化速率变化的关键创新。 PI 将通过结合现场、实验室和计算方法来解决这些问题。将估计滑翔壁虎和相关谱系的完全解析的进化树。将结合外部观察、diceCT 和组织学来调查滑翔和非滑翔壁虎的结构变异。将通过分析一组示例类群中的胚胎形态和发育基因表达模式来评估滑翔类群之间的发育相似性。相对的神秘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。将采用系统发育比较分析来确定该群体的表型和谱系多样化模式及其与形态和功能变化的关系。大量新 DNA 序列数据；形态学数据，包括大量全身 CT 扫描；将产生性能数据，并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.