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

在进化过程中为一种功能服务，但后来又被进化修改为一种新功能的物种特征被称为变异。虽然有很多这样的例子，但它们进化的过程仍然知之甚少。这个项目将推进我们对进化如何重塑物种特征的基因蓝图以创造新的、新颖的创新的理解。与滑翔和飞行有关的特征，如羽毛，是一些最著名的令人兴奋的例子。不幸的是，大多数滑翔物种已经高度专业化，这使得研究灭绝发生的过程变得困难。壁虎，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肤皮瓣进化出多次滑翔结构，有多个物种共同代表了从普通滑翔能力到高度专业化滑翔能力的完全转变。这些进化复制允许研究人员测试特定特征的剔除是否遵循可预测的模式，也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。公众还将参与萨姆·诺布尔博物馆的教育项目，该项目将提供适合年龄的信息和与壁虎滑翔有关的学习活动。这项研究将在进化关系的背景下确定壁虎滑翔相关的期望的后果。两个主要的研究问题将被解决：(1)滑动结构是否代表了以可预测的方式进化的期望；(2)这些特征或相关的功能转移是否代表了导致受影响分支进化速度变化的关键创新。pi将结合现场、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谱系。我们将结合外部观察、解剖学和组织学对滑翔壁虎和非滑翔壁虎的结构变化进行调查。本文将通过分析一组典型分类群的胚胎形态和发育基因表达模式来评估滑行分类群之间的发育相似性。相对隐蔽和滑翔性能值将通过观察活体动物和通过模型实验来记录从伪装到滑翔的功能转变来测量。系统发育比较分析将用于确定表型和谱系多样化模式及其与该群体形态和功能变化的关系。大量新的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，并对科学界具有广泛的兴趣和用途。

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.