Oceanic island museomics: human impact and the natural laboratory paradigm

项目要点-测试自然实验室范式的假设--岛屿是研究进化的理想模型系统--以新颖的方式使用档案收藏来解决新问题--将华威大学的DNA工作与自然历史博物馆的标本馆和实地研究相结合的多学科培训。大洋岛长期以来一直被认为是‘自然实验室’，非常适合于进化的现场研究。它们提供了一些最引人注目的自适应辐射课本例子，并在生物学关键概念的发展中发挥了--并将继续发挥--重要作用。与此同时，它们的生物群具有如此丰富的独特多样性，也是全球最濒危的生物群之一。例如，在亚速尔群岛，据估计，在1439年殖民时，只有不到10%的原生森林幸存下来，而在加那利群岛和复活节岛，古生态数据表明，史前人类调解的优势树种灭绝。最近的灭绝记录--以博物馆和草药馆的标本为依据--在世界各地的许多海洋岛屿上都是已知的。分子生物学的发展，特别是下一代测序技术的发展，有可能极大地扩大“岛屿实验室”的研究范围，以涵盖与岛屿多样化事件的遗传基础有关的基本问题。基因组水平的DNA序列数据的获取为揭示非模式生物的谱系历史提供了前所未有的机会。它使我们能够阐明快速进化的岛屿谱系中以前难以处理的进化关系，并开始了解物种形成事件的基因组基础，确定物种形成所涉及的基因座的数量、遗传差异的性质以及这些基因座控制什么。然而，自然实验室范式假设岛屿上的多样性模式是自然生态和进化过程的结果。它假设人类的影响对这些模式的解释并不重要。这是一个合理的假设吗？考虑到人类对海洋岛屿影响的规模和广度，该项目旨在通过一系列进化问题来检验自然实验室范式的这一假设。方法我们建议使用圣赫勒拿的植物群来检验自然实验室范式的假设。有一些进化过程的经典例子，如适应性辐射；人类对它们的生物群产生了深远的影响，过去三百年是一个深刻变化的时期，植物采集的历史也是如此。我们将重点研究圣赫勒拿的轮藻。下一代测序与古老的DNA技术相结合，将被用于从活的和标本材料中产生这些进化辐射的数据。我们将把仅基于生活材料的推论与那些也包含档案样本的推论进行对比。这将使我们能够阐明范围缩小和灭绝对不同尺度上的系统发育和系统地理问题的影响--从岛屿分支的广泛姐妹分类群关系到种群水平的分析。

Project Highlights - Testing the assumptions of the natural laboratory paradigm - the idea that islands are ideal model systems for studying evolution- Using archival collections in novel ways to address novel questions- Multidisciplinary training integrating aDNA work at University of Warwick with herbarium and field-based research at the Natural History Museum.Oceanic islands have long been recognised as 'natural laboratories', ideally suited for in-situ studies of evolution. They provide some of the most striking, text book examples of adaptive radiations and have played - and continue to play - a major role in the development of key concepts in biology. At the same time, their biota, that are so rich in unique diversity, are also among the most globally endangered. In the Azores, for example, it is estimated that less than 10% of the native forest at the time of colonisation in 1439 survives whilst in the Canaries and in Easter island, palaeoecological data points to pre-historic, human-mediated extinction of dominant tree species. More recent records of extinction - backed by specimens in museums and herbaria - are known from many oceanic islands worldwide. Developments in molecular biology, notably the development of Next Generation Sequencing techniques (NGS) have the potential to greatly extend the scope of studies on 'island laboratories' to encompass fundamental questions relating to the genetic basis of island diversification events. The acquisition of DNA sequence data at the genomic level is providing unprecedented opportunities to uncover the history of lineages in non-model organisms. It is allowing us to elucidate evolutionary relationships in rapidly evolving island lineages that were previously intractable and to start to understand the genomic basis of speciation events, to determine the number of loci involved in speciation, the nature of the genetic differences, and what those loci control.However, the 'natural laboratory' paradigm assumes that diversity patterns on islands are the result of natural ecological and evolutionary processes. It assumes that the impact of humans is not significant for the interpretation of those patterns. Is that a valid assumption? Given the scale and breadth of human impact on oceanic islands, this project aims to test this assumption of the natural laboratory paradigm across a spectrum of evolutionary questions.MethodologyWe propose to test the assumptions of the natural laboratory paradigm using the floras of St Helena. There are classic examples of evolutionary processes such as adaptive radiation; humans have had a profound impact on their biota and there is a history of botanical collecting spanning the last three hundred years, a period of profound change. We will focus the study on Trochetiopsis in St Helena. Next generation sequencing coupled with ancient DNA techniques will be used to generate data from both living and herbarium material for these evolutionary radiations. We will contrast inferences based only on living material with those also incorporating archival samples. This will allow us to elucidate the impact of range reductions and extinctions on phylogenetic and phylogeographic questions at different scales - from broad scale sister taxon relationships of island clades to population-level analyses.