Evolutionary rescue and the limits to phenotypic plasticity: testing theory in the field

进化救援和表型可塑性的限制：现场测试理论

基本信息

批准号：
NE/P001793/1
负责人：
Jonathan Bridle
金额：
$ 52.07万
依托单位：
University of Bristol
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FP001793%2F1
关键词：
Evolutionary rescue limits phenotypic plasticity

项目摘要

Rapid climate change and habitat loss will cause many species to become extinct this century unless they can cope with changing and more extreme ecological conditions. Understanding what limits species' ecological tolerances is therefore an issue of critical scientific importance because it allows us to predict the consequences of ongoing rates of environmental change to populations and therefore to ecological communities. A common way that organisms deal with environmental variation is to be 'plastic', i.e. to change their morphological, physiological or behavioural traits (their phenotypes) directly in response to their local environment, without requiring rapid evolutionary change. Such 'phenotypic plasticity' buffers changes in the environment, and can maintain fitness across the range of environments typically experienced by a species. Currently, most of the global responses of biodiversity to climate change have been ascribed to such phenotypic plasticity, rather than to actual evolutionary change, underlining its importance in maintaining ecological outputs.However, the ability of phenotypic plasticity to cope with environmental change has limits. Not only is maintaining variation in gene expression likely to be energetically expensive, it also evolves to maintain fitness only within the range of environments a species experiences in its recent past. In novel or extreme conditions, there is therefore no reason that a species' plastic responses will still improve their ability to survive and produce offspring. Instead, plastic responses that were adaptive in former environments may actually reduce their fitness in new environments. This idea is especially worrying because it predicts that plasticity will be unable to cope as ecological change continues, leading to sudden population declines as critical environmental limits are exceeded. By contrast, other theoretical models predict that plastic responses will be able to evolve more quickly in novel environments, generating faster evolutionary responses than predicted by laboratory experiments under common garden conditions. We will test these theoretical predictions by measuring the plastic responses of two ecologically divergent species of ragwort (genus Senecio) to changes in their altitudinal position, both within and outside their prevailing distributions on the slopes of Mount Etna, Sicily. These species, Senecio aethnensis and S. chrysanthemifolius differ in a number of phenotypic traits, as well as in the expression of key genes that are associated with adaptation to different altitudes. We will transplant genotypes of both species into a range of field conditions and monitor their performance and plasticity over a two-year period in order to determine each genotype's response to conditions outside its normal ('home') environment. We will measure growth and development parameters, and reproductive parameters as a measure of each genotype's local fitness, and test the degree to which the declines in fitness expected with changes in altitude are offset by plastic changes in their phenotype and in gene expression. We predict that although observed plastic responses will keep individuals healthy and productive under their species' usual range of altitudinal conditions, phenotypic responses will no longer be appropriate with altitudinal changes beyond these limits. Such an empirical finding will have important implications for predicting the continued ability of species to respond plastically to climate change. In particular, it will suggest, the rapid evolution will be necessary to prevent population and species' extinction where rates of environmental change exceed prevailing conditions within their geographical range.

快速的气候变化和栖息地丧失将导致许多物种在本世纪灭绝，除非它们能够应对不断变化和更极端的生态条件。因此，了解限制物种生态耐受性的因素是一个具有至关重要科学意义的问题，因为它使我们能够预测持续的环境变化速度对种群乃至生态群落的影响。生物体应对环境变化的常见方式是“可塑性”，即直接改变其形态、生理或行为特征（其表型）以响应其当地环境，而不需要快速的进化变化。这种“表型可塑性”可以缓冲环境的变化，并且可以在一个物种通常经历的各种环境中保持适应性。目前，全球生物多样性对气候变化的大部分反应都归因于这种表型可塑性，而不是实际的进化变化，这凸显了其在维持生态产出方面的重要性。然而，表型可塑性应对环境变化的能力是有限的。维持基因表达的变异不仅可能需要耗费大量精力，而且它的进化也只能在物种最近经历的环境范围内维持适应性。因此，在新的或极端的条件下，一个物种的塑料反应没有理由仍然会提高其生存和繁殖后代的能力。相反，在以前环境中适应性的塑料反应实际上可能会降低它们在新环境中的适应性。这个想法尤其令人担忧，因为它预测随着生态变化的持续，可塑性将无法应对，导致人口突然下降，因为超过了关键的环境限制。相比之下，其他理论模型预测，塑料反应将能够在新环境中更快地进化，产生比常见花园条件下实验室实验预测的更快的进化反应。我们将通过测量两种生态上不同的千里光属物种对其海拔位置变化的塑性反应来检验这些理论预测，无论是在西西里岛埃特纳火山山坡上的主要分布范围内还是之外。这些物种千里光（Senecio aethnensis）和菊花千里光（S. chrysanthemifolius）在许多表型特征以及与适应不同海拔相关的关键基因的表达方面存在差异。我们将把这两个物种的基因型移植到一系列野外条件中，并在两年内监测它们的表现和可塑性，以确定每种基因型对其正常（“家庭”）环境之外的条件的反应。我们将测量生长和发育参数以及生殖参数，作为每种基因型局部适应性的衡量标准，并测试预期随着海拔变化而导致的适应性下降被其表型和基因表达的可塑性变化所抵消的程度。我们预测，尽管观察到的可塑性反应将使个体在其物种通常的海拔条件范围内保持健康和生产力，但当海拔变化超出这些限制时，表型反应将不再适用。这样的实证发现对于预测物种对气候变化做出可塑性反应的持续能力具有重要意义。特别是，它将表明，当环境变化速度超过其地理范围内的普遍条件时，快速进化对于防止人口和物种灭绝是必要的。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Plasticity and the costs of incorrect responses.

可塑性和错误反应的成本。

DOI：
10.1016/j.tree.2022.11.012
发表时间：
2023
期刊：
Trends in ecology & evolution
影响因子：
16.8
作者：
Hoffmann AA
通讯作者：
Hoffmann AA

Understanding the biology of species' ranges: when and how does evolution change the rules of ecological engagement?

DOI：
10.1098/rstb.2021.0027
发表时间：
2022-04-11
期刊：
Philosophical transactions of the Royal Society of London. Series B, Biological sciences
影响因子：
0
作者：
Bridle J;Hoffmann A
通讯作者：
Hoffmann A

Senecio as a model system for integrating studies of genotype, phenotype and fitness.

DOI：
10.1111/nph.16434
发表时间：
2020-01
期刊：
The New phytologist
影响因子：
0
作者：
Greg M. Walter;R. Abbott;A. Brennan;J. Bridle;M. Chapman;James W. Clark;D. Filatov;B. Nevado
通讯作者：
Greg M. Walter;R. Abbott;A. Brennan;J. Bridle;M. Chapman;James W. Clark;D. Filatov;B. Nevado

Hidden genetic variation in plasticity provides the potential for rapid adaptation to novel environments.

可塑性中隐藏的遗传变异提供了快速适应新环境的潜力。