Macroevolution in planktonic foraminifera

浮游有孔虫的宏观进化

• 批准号: NE/E015956/1
• 负责人: Andy Purvis
• 金额: $ 34.35万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FE015956%2F1
• 关键词: Macroevolution; planktonic; foraminifera

This project aims to provide a more detailed, precise and comprehensive understanding than has so far been possible of how ecology and environments shape the evolution of biodiversity in a group of organisms over a long period of time. Over millions of years, species arise, change, give rise to new species and then go extinct. There is clear evidence that the speed with which these things happen varies among species and over time: biodiversity is too unevenly spread among different groups of organisms for them all to have been diversifying in the same way, and the fossil record shows that there have been times when the risk of extinction has been particularly high. However, it has proved very hard to work out exactly why some species have thrived and others died out, or why some times are better and others worse. For most groups, we know most about present-day diversity, so can relate numbers of species to particular characteristics, like small size or being able to fly. Such analyses, however, don't tell us whether those characteristics affect the rate at which species are formed, the rate of extinction, or both. Nor can they give us direct information about how the processes shaping biodiversity have changed over time. The fossil record has direct information about the past, but it is often too patchy to tell us much about detailed processes at the level of individual species and lineages. The planktonic foraminifera have probably the best fossil record of any group over the past 65 million years. These single-celled, often beautiful, organisms are found in vast numbers in seas throughout the world. For tens of millions of years, billions of individuals have rained down on the sea bed, often forming thick sediments. To go down into these sediments is to go back in time in foram evolution, and the sheer numbers of fossils make it possible to reconstruct their history in unparalleled detail. Their evolutionary relationships can be pieced together, and each species characterised: physical dimensions can be measured, and ecology inferred from chemical analysis. The sediments, and other sources of data, also tell us when each fossil lived, and what its world was like. This combination of information makes it possible to understand in unprecedented detail the 'rules' governing foram evolution. How have rates of speciation and extinction changed through the last 65 million years? Does high diversity suppress speciation, cause extinction, neither, or both? Do individual species' probabilities of speciating or going extinct in the next slice of time depend on how old they are? Which ecological characters shape speciation and extinction rates? Does the tendency towards larger size stem solely from within-species changes, or does size affect speciation and extinction rates too? How do morphological characters evolve over time, and is the rate of their evolution tied up with rates of diversification? And how constant have these 'rules' been through time? Are there different sets of rules when extinction rates are high, as opposed to normal; or when climate is changing, as opposed to stable? Some of these questions have been tackled before in some groups of organisms, but planktonic forams provide the opportunity to gain a synthetic overview of how large-scale patterns in evolution arise in natural environments. Such an overview would be valuable to all researchers looking at macroevolution, because it is not possible to look at most of these questions rigorously in most other groups of organisms: having a detailed picture of one 'model' system will help researchers working on other groups too.

这个项目旨在提供一个更详细、精确和全面的理解，比迄今为止可能的生态和环境如何在很长一段时间内塑造一组生物多样性的进化。在数百万年的时间里，物种出现，变化，产生新物种，然后灭绝。有明确的证据表明，这些事情发生的速度因物种和时间的不同而不同：生物多样性在不同生物群体之间的分布太不均匀，它们不可能都以同样的方式多样化，化石记录表明，曾经有过灭绝风险特别高的时期。然而，事实证明，要弄清楚为什么有些物种繁荣而另一些物种灭绝，或者为什么有些时候更好，有些时候更糟，是非常困难的。对于大多数种群，我们最了解当今的多样性，因此可以将物种数量与特定特征联系起来，比如体型小或会飞。然而，这样的分析并没有告诉我们这些特征是否会影响物种形成的速度，灭绝的速度，或者两者兼而有之。它们也不能给我们提供关于形成生物多样性的过程如何随时间变化的直接信息。化石记录有关于过去的直接信息，但它往往太不完整，不能告诉我们很多关于个体物种和谱系水平上的详细过程。在过去的6500万年里，浮游有孔虫可能拥有最好的化石记录。这些单细胞的、通常很漂亮的生物在世界各地的海洋中大量存在。几千万年来，数十亿的个体像雨点一样落在海床上，经常形成厚厚的沉积物。深入到这些沉积物中就是回到有孔虫的进化过程中，化石的数量之多使得以无与伦比的细节重建它们的历史成为可能。它们的进化关系可以拼凑在一起，每个物种都有自己的特征：可以测量物理尺寸，从化学分析中推断生态。沉积物和其他数据来源也告诉我们每个化石生活的时间，以及它的世界是什么样的。这些信息的结合使我们有可能以前所未有的细节理解控制有孔虫进化的“规则”。在过去的6500万年里，物种形成和灭绝的速度是如何变化的？高多样性是否抑制物种形成，导致灭绝，两者都没有，还是两者都有？单个物种在下一段时间内形成或灭绝的概率是否取决于它们的年龄？哪些生态特征决定了物种形成和灭绝速度？体型变大的趋势是否仅仅源于物种内部的变化，还是体型也会影响物种的形成和灭绝速度？形态特征是如何随着时间的推移而进化的，它们的进化速度是否与多样化的速度联系在一起？随着时间的推移，这些“规则”有多稳定？与正常情况相比，当物种灭绝率很高时，是否有不同的规则？或者当气候变化而不是稳定时？其中一些问题以前已经在一些生物群体中得到了解决，但浮游有孔虫提供了一个机会，让我们对自然环境中大规模进化模式的产生有了一个综合的概述。这样的概述对所有研究宏观进化的研究人员都是有价值的，因为在大多数其他生物群体中不可能严格地研究大多数这些问题：拥有一个“模型”系统的详细图片也将有助于研究其他群体的研究人员。

项目成果

paleoPhylo: free software to draw paleobiological phylogenies

• DOI: 10.1666/0094-8373-35.3.460
• 发表时间: 2009-06-01
• 期刊: PALEOBIOLOGY
• 影响因子: 2.7
• 作者: Ezard, Thomas H. G.;Purvis, Andy
• 通讯作者: Purvis, Andy

How sensitive are elasticities of long-run stochastic growth to how environmental variability is modelled?

• DOI: 10.1016/j.ecolmodel.2009.09.017
• 发表时间: 2010-01
• 期刊: Ecological Modelling
• 影响因子: 3.1
• 作者: T. H. Ezard;T. Coulson

Speciation and Patterns of Diversity

• DOI: 10.1093/sysbio/syq014
• 发表时间: 2010-05
• 期刊: Systematic Biology
• 影响因子: 6.5
• 作者: F. Bokma

Inclusion of a near-complete fossil record reveals speciation-related molecular evolution

• DOI: 10.1111/2041-210x.12089
• 发表时间: 2013-08-01
• 期刊: METHODS IN ECOLOGY AND EVOLUTION
• 影响因子: 6.6
• 作者: Ezard, Thomas H. G.;Thomas, Gavin H.;Purvis, Andy
• 通讯作者: Purvis, Andy