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.

迅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，除非它们能够应对变化和更极端的生态条件。因此，了解什么限制物种的生态公差是一个至关重要的科学重要性问题，因为它使我们能够预测持续的环境变化对人口以及生态社区的后果。有机体处理环境变化的一种常见方法是“塑性”，即直接响应其当地环境而不需要快速进化变化，将其形态，生理或行为特征（其表型）直接改变。这种“表型可塑性”缓冲环境中会发生变化，并可以在物种通常经历的环境范围内保持适应性。当前，生物多样性对气候变化的大多数全球反应都归因于这种表型可塑性，而不是实际的进化变化，强调了其在维持生态产量中的重要性。不仅要保持基因表达的变化可能在能量上很昂贵，而且还可以在物种最近的过去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，没有理由将物种的塑料反应仍然可以提高其生存和产生后代的能力。取而代之的是，在以前的环境中自适应的塑料反应实际上可能会降低其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，可塑性将无法应付，因为超出了关键的环境限制，导致人口突然下降。相比之下，其他理论模型预测，塑料反应将能够在新颖的环境中更快地发展，从而产生比在常见花园条件下实验室实验所预测的更快的进化反应。我们将通过测量两种生态不同的Ragwort物种（Senecio属）的塑性响应来测试这些理论预测，以在其高度位置的变化，无论是在其山坡上的普遍分布的内外，eTna Mount eTna的山坡上的变化。这些物种，塞内西奥·艾斯尼斯（Senecio Aethnensis）和菊花链球菌（S. chrysanthemifolius）在许多表型特征以及与适应不同高度有关的关键基因的表达中有所不同。我们将把这两种物种的基因型移植到一系列田间条件中，并在两年内监测其性能和可塑性，以确定每个基因型对正常（“家庭”）环境之外条件的反应。我们将测量生长和发育参数，以及生殖参数，以衡量每个基因型的局部适应性，并测试预期的适应性下降的程度，而高度变化的变化被其表型和基因表达的塑性变化所抵消。我们预测，尽管观察到的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，但表型反应将不再适合这些限制的高度变化。这样的经验发现将对预测物种对气候变化做出塑料反应的能力具有重要意义。它特别表明，要防止人口和物种的灭绝，环境变化率超过其地理范围内的主要条件，将需要快速发展。

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

Environmental effects on genetic variance are likely to constrain adaptation in novel environments