Evolution caused by extreme events

Abstract

One contribution of 14 to a theme issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic ( pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'.

Behavioural, ecological and evolutionary responses to extreme climatic events: challenges and directions

“…There has been long-standing recognition of the importance of ECEs by particularly paleo-ecologists and macro-evolutionary biologists (e.g. [7], but see also [8,9]), but recently-in the face of anthropogenic climate change-ECEs have received much stronger interest in the wider ecological and evolutionary community. Consequently, the number of biological papers on ECEs is now increasing exponentially (e.g.…”

“…geological) time intervals. They are also known for their enormity of biological impact, causing planetary environmental regime shifts (with biotic feedbacks possibly causing further drastic changes) and mass organismal extinctions, and driving macro-evolution [7].…”

“…the value of single event studies [17]). Another goal was to invite contributions from different fields that synthesize the ecological [2,18] and evolutionary literature on ECEs [7,35] and combine this with research papers that illustrate ways to make progress in answering important and interesting conceptual questions. The inclusion of contributions from such disparate fields as behavioural plasticity [23], community ecology [18] and evolution of thermal tolerance [35] was specifically chosen to highlight that these fields deal with similar challenges (e.g.…”

“…Another major parallel among studies in this theme issue appears to be that responses are highly idiosyncratic, indicating that generalization of ECE impacts is difficult and predictability low. For example, evolutionary responses in thermal tolerance in response to extremes can depend on the climatic history and amount of variability organisms previously experienced [35], and evolutionary change is often strongly mediated by changes in species interactions, which vary widely among ecosystems [7]. Behaviourally plastic responses may depend on the habitat type individuals live in [23] or on their energy reserves [20], while demographic responses can be highly age-dependent [34].…”

“…We should also make optimal use of the limited information we already have, which includes learning from the many anecdotal single events studies that currently dominate the literature [17]. Notwithstanding, it is clear that insights on the long-term ecological and evolutionary consequences of ECEs can only be derived from long-term studies [7,10,17]. To address this challenge, we may need to focus on model systems in which ECEs are becoming rapidly either more frequent and severe (e.g.…”