Phenotypic innovation through time and space

生物多样性的起源和维持是理解和减轻目前第六次大规模灭绝影响的关键。生物多样性随时间变化的一个核心方面是物种的特征如何随着环境的变化而变化。宏观进化生物学家提出了两个关键机制：精细加工，特征可以随着时间的推移而改变，沿着“进化阻力最小的路线”沿着进行渐进式修改。（例如，在地理梯度上大小的逐渐变化）或创新，新的独特特征迅速出现，远离进化阻力最小的路线（例如，物种进化出新的表型特征，例如在岛屿上）。虽然这些机制已被广泛研究，我们对创新或精心设计如何影响生物多样性没有明确的理解，因为研究仅限于小范围的特定群体，时间尺度我们还缺乏一个可推广的创新和阐述的概念，以及适当的方法和数据集，用于理解跨谱系和时空尺度的表型和生物多样性之间的关系。通过提出一种新的研究特质进化的概念和方法，我将回答以下关键问题：1）生态机会是否产生创新？2)创新在空间、时间和血统上都是可预测的吗？3）创新是否预示着空间、时间和血统上的差异和多样性？我将通过开发1）一个新的概念框架来实现这一目标，以评估不同时空尺度上的精细化和创新对性状进化的相对贡献; 2）一套新的方法工具来衡量精细化和创新; 3）跨越不同时间尺度和谱系的两个数据集提供了可概括的答案。具体而言，我将：1）通过将它们分别定义为一个物种或一个进化枝在任何性状空间中的“最小进化阻力线”上的数学投影和拒绝，将这条线定义为使用系统发育广义混合效应模型测量的性状方差-协方差矩阵的特征向量，来概括阐述和创新的概念。2)将这一新的概念和方法应用于两个对比的现生鸟类（8748种）和化石哺乳动物（177种）数据集，在不同的时空尺度上回答上述三个问题。3)在R中将此方法作为一个包实现，使其适用于回答不同数据集上的多个特定问题。这将使我们能够估计表型创新和精心制作如何通过时间和空间塑造生物多样性，揭示导致我们今天观察到的惊人生物多样性的机制。

The origins and maintenance of biodiversity are key to understanding and mitigating the effects of the current sixth mass extinction. One central aspect of biodiversity-change-through-time is how species' traits change in relation to changes in their environment. Macroevolutionary biologist have proposed two key mechanisms: elaboration, where traits can change over time with incremental modifications along a "line of evolutionary least resistance" (e.g. the gradual change of size across a geographical gradient) or innovation where new distinct traits arise rapidly and away from the line of evolutionary least resistance (e.g. species evolving new phenotypic features, for example on islands).While these mechanisms have been widely studied, we have no clear understanding of how innovation or elaboration impact biodiversity because research has been limited to specific groups at small spatio-temporal scales. We also lack a generalisable concept of innovation and elaboration and appropriate methods and datasets for understanding the relationship between phenotype and biodiversity across lineages and spatio-temporal scales. By proposing a novel conceptual and methodological approach to study trait evolution, I will answer the following key questions: 1) Does ecological opportunity generate innovation? 2) Is innovation predictable across space, time and lineages? and 3) Does innovation predict disparity and diversity across space, time, and lineages?I will achieve this by developing 1) a novel conceptual framework to evaluate the relative contribution of elaboration and innovation to trait evolution across different spatio-temporal scales; 2) a set of new methodological tools to measure elaboration and innovation and 3) two datasets spanning across different time scales and lineages provide generalisable answers. Specifically, I will: 1) Generalise the concepts of elaboration and innovation by defining them as, respectively, the mathematical projection and rejection of a species or a clade onto a "line of least evolutionary resistance" in any trait space, defining this line as the eigenvector of the traits variance-covariance matrix measured using phylogenetic generalised mixed effect models. 2) Apply this new concept and method to two contrasting datasets of living birds (8748 species) and fossil mammals (177 species) to answer the three questions above across different spatio-temporal scales. 3) Implement this approach as a package in R to make it applicable for answering multiple specific questions across different datasets. This will allow us to estimate how phenotypic innovation and elaboration has shaped biodiversity through time and space, shedding light on the mechanisms that lead to the amazing biodiversity we observe today.