Beyond buying time: the role of plasticity in phenotypic adaptation to rapid environmental change

Abstract

How populations and species respond to modified environmental conditions is critical to their persistence both now and into the future, particularly given the increasing pace of environmental change. The process of adaptation to novel environmental conditions can occur via two mechanisms: (1) the expression of phenotypic plasticity (the ability of one genotype to express varying phenotypes when exposed to different environmental conditions), and (2) evolution via selection for particular phenotypes, resulting in the modification of genetic variation in the population. Plasticity, because it acts at the level of the individual, is often hailed as a rapid-response mechanism that will enable organisms to adapt and survive in our rapidly changing world. But plasticity can also retard adaptation by shifting the distribution of phenotypes in the population, shielding it from natural selection. In addition to which, not all plastic responses are adaptive—now well-documented in cases of ecological traps. In this theme issue, we aim to present a considered view of plasticity and the role it could play in facilitating or hindering adaption to environmental change. This introduction provides a re-examination of our current understanding of the role of phenotypic plasticity in adaptation and sets the theme issue's contributions in their broader context. Four key themes emerge: the need to measure plasticity across both space and time; the importance of the past in predicting the future; the importance of the link between plasticity and sexual selection; and the need to understand more about the nature of selection on plasticity itself. We conclude by advocating the need for cross-disciplinary collaborations to settle the question of whether plasticity will promote or retard species' rates of adaptation to ever-more stressful environmental conditions. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.

Animal learning as a source of developmental bias

“…Subsequent research established that food washing is common in several species of macaques, which means that this particular innovation involved the application of an established behavior to a novel food (Reader & Laland, 2003). There is a lot of interest currently in whether organisms adapt to the rapidly changing world, and the role that plasticity plays in this (Fox, Donelson, Schunter, Ravasi, & Gaitán-Espitia, 2019;Snell-Rood et al, 2018), but few articles in a recent special edition on this topic (Fox et al, 2019) even mention learning. Behavioural innovation through learning commonly allows the generalization or new application of a behavioral phenotype to novel environments or contexts, as well as the de novo invention of novel solutions.…”

“…In fact, many animal innovations fall into this category of established behavior applied in a novel context, or to a novel stimulus (Reader & Laland, 2003;Reader et al, 2016). Nonetheless, this community have stressed how the processes of plasticity and adaptation, traditionally considered independently of each other, need to be viewed synergistically (Fox et al, 2019). There is a lot of interest currently in whether organisms adapt to the rapidly changing world, and the role that plasticity plays in this (Fox, Donelson, Schunter, Ravasi, & Gaitán-Espitia, 2019;Snell-Rood et al, 2018), but few articles in a recent special edition on this topic (Fox et al, 2019) even mention learning.…”

“…There is a lot of interest currently in whether organisms adapt to the rapidly changing world, and the role that plasticity plays in this (Fox, Donelson, Schunter, Ravasi, & Gaitán-Espitia, 2019;Snell-Rood et al, 2018), but few articles in a recent special edition on this topic (Fox et al, 2019) even mention learning. Nonetheless, this community have stressed how the processes of plasticity and adaptation, traditionally considered independently of each other, need to be viewed synergistically (Fox et al, 2019). Greater attention to how animals adjust to novel environments through learning is surely merited.…”

“…Recent studies have demonstrated strong phenotypic changes in organisms in response to urban and other anthropogenic environments, ranging from supplemental feeding affecting beak shape in garden birds, to earthworms and insects evolving tolerance of pollutants (Alberti, 2015;Alberti et al, 2017;Palkovacs, Kinnison, Correa, Dalton, & Hendry, 2012;Sullivan, Bird, & Perry, 2017). Anthropogenic change studies suggest plasticity is important to evolutionary responses (Fox et al, 2019;Snell-Rood et al, 2018), and the field could benefit from greater consideration of the role played by animal learning in these adaptive responses.…”

Phenotypic plasticity as a mechanism of cave colonization and adaptation

“…An instance of standing genetic variation has been reported in A. mexicanus CF with respect to the evolution of eye reduction [22], but phenotypic plasticity has not been studied extensively in this system (but see [23]). This is surprising since phenotypic plasticity plays an important role in the adaptation of many different organisms to changing environments and the colonization of new habitats (reviewed in 24,25).…”