The dangers of irreversibility in an age of increased uncertainty: revisiting plasticity in invertebrates
The dangers of irreversibility in an age of increased uncertainty: revisiting plasticity in invertebrates
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DOI：
10.1111/oik.08715
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发表时间：
2021-10-12
期刊：
影响因子：
3.4
通讯作者：
Bridle, Jon
中科院分区：
文献类型：
--
作者：
Hoffmann, Ary A.;Bridle, Jon
性状对环境条件的可塑性可以增加适合度，扩大基因可以产生可存活和多产表型的环境范围，从而扩大种群在生态空间中持续存在和多样化的时间和地点。无脊椎动物的可塑性适应形式多种多样，从多物性和滞育到行为温度调节和最佳觅食。环境变化和发展限制的地方模式将决定这些形式中的哪一种演变。在这里，我们回顾了无脊椎动物利用狭窄的发育窗口来获得特定类型的表型变化的核心思想，降低了它们的可逆性，同时增加了它们的幅度。这些权衡决定了可塑性在缓冲环境变化方面的成本和有效性。特别是，当预测的环境挑战没有成为现实，或者当环境以不可预测的方式发生变化时，对狭窄的发展或环境窗口的塑料反应会增加健康成本。然后，我们探讨了相反的观点，即增加性状的可逆性取决于延长基因型对环境敏感的时期，但也缩小了可以产生的塑料表型的范围。综合考虑这些发现，我们预计可逆可塑性与不可逆可塑性的成本、收益和限制因素会影响对快速变化和新环境的适应性反应的速度和幅度。然而，这样的预测很少得到检验，也很少被纳入理论模型。认识到这一知识差距使我们提出了新的研究方向，以更深入地了解无脊椎动物和其他生物的可塑性进化。我们通过果蝇适应热应激的例子来说明这些可能的方向。
Plasticity in traits in response to environmental conditions can increase fitness, expanding the range of environments within which a genotype can generate viable and productive phenotypes, and therefore when and where populations can persist and diversify in ecological space. Adaptive forms of plasticity in invertebrates are diverse, ranging from polyphenism and diapause to behavioural thermoregulation and optimal foraging. Local patterns of environmental variation and developmental constraints will dictate which of these forms evolves. Here we review the core idea that the use of narrow developmental windows by invertebrates to attain specific types of phenotypic changes reduces their reversibility, while increasing their magnitude. These tradeoffs dictate the costs and effectiveness of plasticity in buffering environmental variation. In particular, plastic responses to narrow developmental or environmental windows increase fitness costs when predicted environmental challenges do not materialise, or when the environment changes in unpredictable ways. We then explore the converse idea that increasing trait reversibility depends on extending the period for which genotypes are sensitive to the environment, but also narrows the range of plastic phenotypes that can be generated. Considering these findings together, we would expect that the costs, benefits and constraints of reversible versus irreversible plasticity affect the rate and magnitude of adaptive responses to rapidly changing and novel environments. However, such predictions have rarely been tested or included in theoretical models. Identifying this knowledge gap leads us to propose new research directions to provide a deeper understanding of the evolution of plasticity in invertebrates and other organisms. We illustrate these possible directions through examples of Drosophila adapting to thermal stress.