The Effect Of Body Size On The Origin And Diversification Of Birds

体型大小对鸟类起源和多样化的影响

• 批准号: NE/X012395/1
• 负责人: Ryan Felice
• 金额: $ 10.27万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX012395%2F1
• 关键词: Effect; Body; Size; Origin; Diversification

Sixty-six million years ago, the end of the Cretaceous period was marked by one of earth's largest mass extinctions. This event resulted in the demise of three quarters of all land animals, including all of the non-avian dinosaurs and many of the birds. Only a few bird species survived, and these groups subsequently diversified into the stunning variety of species we see today. What allowed these few lucky birds to survive? The factors that predispose organisms to extinction or speciation is of the biggest questions in evolutionary biology. This is increasingly important as more species become threatened with extinction today as a result of human-caused climate change. One hypothesis, the "Lilliput effect," proposes that lower body mass increases the chances of survival during a mass extinction. This is because body size affects nearly every aspect of biology, from life span to metabolism to rate of mutations. Although many studies have sought to quantify whether body size and diversification are linked, nearly all of these have excluded a key source of data: the fossil record. This is despite the fact that mathematical simulations predict that calculating extinction rates without including extinct species invariably produces inaccurate results. Here, we seek to answer two main research questions: (1) how did body size affect speciation and extinction rates in birds over the past 175 million years? (2) how does including fossil data in our models affect our reconstructions of diversification through time? We will use measurements of fossil bird skeletons to reconstruct body mass in approximately 400 extinct avian species, including some of the largest birds ever to exist such as the dodo, great auk, and elephant bird. We will then generate a comprehensive family tree of birds including >10,000 fossil and modern species, allowing us to track their evolutionary history through time. Finally, we will use evolutionary modelling to test whether the probability of speciation and extinction are indeed affected by body mass. Using advanced statistical methods and fossil data, we will provide the first test of the hypothesis that small size was a key trait that allowed birds to diversify after the time of the dinosaurs.

6600万年前，白垩纪时期的结束是地球上最大的巨大灭绝之一。这项事件导致了所有陆地动物中四分之三的灭亡，包括所有非阿奇恐龙和许多鸟类。只有少数几只鸟类幸存下来，这些群体随后将我们今天看到的各种物种多样化。是什么让这几只幸运的鸟能够生存？使生物体灭绝或物种形成的因素是进化生物学中最大的问题。这越来越重要，因为由于人为引起的气候变化，今天越来越多的物种受到灭绝的威胁。一种假设是“利利普特效应”，提出较低的体重会增加质量消灭期间生存的机会。这是因为身体大小几乎影响生物学的各个方面，从生命跨度到新陈代谢再到突变率。尽管许多研究试图量化体型和多样化是否联系在一起，但几乎所有这些都排除了数据的关键来源：化石记录。尽管数学模拟预测，计算灭绝率而不包括灭绝物种总是会产生不准确的结果。在这里，我们试图回答两个主要的研究问题：（1）在过去的1.75亿年中，身体大小如何影响鸟类的物种形成和灭绝率？ （2）在我们的模型中包括化石数据如何影响我们的多元化重建？我们将使用化石鸟骨架的测量来重建大约400种灭绝的鸟类中的体重，其中包括有史以来最大的鸟类，例如渡渡鸟，大艾克和大象鸟。然后，我们将生成一棵全面的鸟类树，其中包括> 10,000种化石和现代物种，使我们能够随着时间的流逝跟踪其进化史。最后，我们将使用进化模型来测试形成和灭绝的概率是否确实受体重影响。使用先进的统计方法和化石数据，我们将提供第一个测试，即小型是一个关键特征，允许鸟类在恐龙之后多样化。