Over the last decade, it has become clear that most animals learn including short lived and non-social ones. Although learning is expected to increase adaptation to rapidly changing environments, this remains poorly documented. Our experimental work focus on one type of rapid environmental change, the climate crisis, because it is the human-induced environmental change best documented for its negative effects on biodiversity.
Learning is well studied in the context of sexual selection, which is an important evolutionary force to consider for quantifying adaptation of organisms to changing environments because it can work against natural selection. Maladaptation may occur when individuals prefer one resource (e.g., one type of mates) that reduces the fitness compared to other available resources. So far, how learning affects animal responses to the climate crisis by producing adaptive or maladaptive, learned sexual behaviours remains virtually unexplored.
We used as a model the tropical butterfly Bicyclus anynana displaying wet (warm) and dry (colder) season forms that match the alternation of African seasons. We found that a learned mate preference produces maladaptation at three levels under climate change, each of which may be enough to put populations at risk of rapid extinction by 2100 after climate has warmed. Worryingly, learned sexual behaviours were reversed compared to those displayed by naïve individuals; hence ignoring learning in adaptation to climate change may lead to seriously erroneous conclusions. We discuss how general our results may be for other insects and other animals. Altogether, we argue that we need to take a more integrative account of animal responses to human-induced, environmental threats, to predict their extinction risk.
Nature of Life seminars
Date : 12 May 2020
Time : 15.45 hours