Ecology Letters

Rönkä, Katja; Valkonen, Janne K.; Nokelainen, Ossi; Rojas, Bibiana; Gordon, Swanne; Burdfield‐Steel, Emily; Mappes, Johanna; Grether, Greg

doi: 10.1111/ele.13597pmid: 32881319

Warning signals are predicted to develop signal monomorphism via positive frequency‐dependent selection (+FDS) albeit many aposematic systems exhibit signal polymorphism. To understand this mismatch, we conducted a large‐scale predation experiment in four countries, among which the frequencies of hindwing warning coloration of the aposematic moth, Arctia plantaginis, differ. Here we show that selection by avian predators on warning colour is predicted by local morph frequency and predator community composition. We found +FDS to be the strongest in monomorphic Scotland and lowest in polymorphic Finland, where the attack risk of moth morphs depended on the local avian community. +FDS was also found where the predator community was the least diverse (Georgia), whereas in the most diverse avian community (Estonia), hardly any models were attacked. Our results support the idea that spatial variation in predator communities alters the strength or direction of selection on warning signals, thus facilitating a geographic mosaic of selection.

Castledine, Meaghan; Padfield, Daniel; Buckling, Angus; Fukami, Tadashi

doi: 10.1111/ele.13599pmid: 32893477

Interspecific coevolutionary interactions can result in rapid biotic adaptation, but most studies have focused only on species pairs. Here, we (co)evolved five microbial species in replicate polycultures and monocultures and quantified local adaptation. Specifically, growth rate assays were used to determine adaptations of each species’ populations to (1) the presence of the other four species in general and (2) sympatric vs. allopatric communities. We found that species did not show an increase in net biotic adaptation:ancestral, polyculture‐ and monoculture‐evolved populations did not have significantly different growth rates within communities. However, 4/5 species’ growth rates were significantly lower within the community they evolved in relative to an allopatric community. ‘Local maladaptation’ suggests that species evolved increased competitive interactions to sympatric species’ populations. This increased competition did not affect community stability or productivity. Our results suggest that (co)evolution within communities can increase competitive interactions that are specific to (co)evolved community members.

Sánchez‐Tójar, Alfredo; Lagisz, Malgorzata; Moran, Nicholas P.; Nakagawa, Shinichi; Noble, Daniel W. A.; Reinhold, Klaus; Munch, Stephan

doi: 10.1111/ele.13479pmid: 32844521

A recent meta‐analysis concluded, ‘transgenerational effects are widespread, strong and persistent’. We identify biases in the literature search, data and analyses, questioning that conclusion. Re‐analyses indicate few studies actually tested transgenerational effects – making it challenging to disentangle condition‐transfer from anticipatory parental effects, and providing little insight into the underlying mechanisms.

Lemaître, Jean‐François; Gaillard, Jean‐Michel; Ramm, Steven A.; Salguero‐Gomez, Roberto

doi: 10.1111/ele.13593pmid: 32906225

Ageing and sexual selection are intimately linked. There is by now compelling evidence from studies performed across diverse organisms that males allocating resources to mating competition incur substantial physiological costs, ultimately increasing ageing. However, although insightful, we argue here that to date these studies cover only part of the relationship linking sexual selection and ageing. Crucially, allocation to traits important in post‐copulatory sexual selection, that is sperm competition, has been largely ignored. As we demonstrate, such allocation could potentially explain much diversity in male and female ageing patterns observed both within and among species. We first review how allocation to sperm competition traits such as sperm and seminal fluid production depends on the quality of resources available to males and can be associated with a wide range of deleterious effects affecting both somatic tissues and the germline, and thus modulate ageing in both survival and reproductive terms. We further hypothesise that common biological features such as plasticity, prudent sperm allocation and seasonality of ejaculate traits might have evolved as counter‐adaptations to limit the ageing costs of sperm competition. Finally, we discuss the implications of these emerging ageing costs of sperm competition for current research on the evolutionary ecology of ageing.

Ellner, Stephen P.; Snyder, Robin E.; Adler, Peter B.; Hooker, Giles; Schreiber, Sebastian J.; Coulson, Tim

doi: 10.1111/ele.13580pmid: 32851766

Pande et al. (2020) point out that persistence time can decrease even as invader growth rates (IGRs) increase, which potentially undermines modern coexistence theory. However, because persistence time increases rapidly with system size only when IGR > 0, to understand how any real community persists, we should first identify the mechanisms producing positive IGR.

doi: 10.1111/ele.13316pmid: N/A

Liu, Chunlong; Wolter, Christian; Xian, Weiwei; Jeschke, Jonathan M.; Bertelsmeier, Cleo

doi: 10.1111/ele.13577pmid: 32881373

The reliability of transferring species distribution models (SDMs) to new ranges and future climates has been widely debated. Biological invasions offer the unique opportunity to evaluate model transferability, as distribution data between species’ native and introduced ranges are geographically independent of each other. Here, we performed the first global quantitative synthesis of the spatial transferability of SDMs for 235 invasive species and assessed the association of model transferability with the focal invader, model choice and parameterisation. We found that SDMs had limited spatial transferability overall. However, model transferability was higher for terrestrial endotherms, species introduced from or to the Southern Hemisphere, and species introduced more recently. Model transferability was also positively associated with the number of presences for model calibration and evaluation, respectively, but negatively with the number of predictors. These findings highlight the importance of considering the characteristics of the focal invader, environment and modelling in the application and assessment of SDMs.

Maliet, Odile; Loeuille, Nicolas; Morlon, Hélène; Poisot, Timothée

doi: 10.1111/ele.13592pmid: 32885919

How ecological interaction networks emerge on evolutionary time scales remains unclear. Here we build an individual‐based eco‐evolutionary model for the emergence of mutualistic, antagonistic and neutral bipartite interaction networks. Exploring networks evolved under these scenarios, we find three main results. First, antagonistic interactions tend to foster species and trait diversity, while mutualistic interactions reduce diversity. Second, antagonistic interactors evolve higher specialisation, which results in networks that are often more modular than neutral ones; resource species in these networks often display phylogenetic conservatism in interaction partners. Third, mutualistic interactions lead to networks that are more nested than neutral ones, with low phylogenetic conservatism in interaction partners. These results tend to match overall empirical trends, demonstrating that structures of empirical networks that have most often been explained by ecological processes can result from an evolutionary emergence. Our model contributes to the ongoing effort of better integrating ecological interactions and macroevolution.

Metz, Johannes; Lampei, Christian; Bäumler, Laura; Bocherens, Hervé; Dittberner, Hannes; Henneberg, Lorenz; Meaux, Juliette; Tielbörger, Katja; Salguero‐Gomez, Roberto

doi: 10.1111/ele.13596pmid: 32851791

Rapid evolution of traits and of plasticity may enable adaptation to climate change, yet solid experimental evidence under natural conditions is scarce. Here, we imposed rainfall manipulations (+30%, control, −30%) for 10 years on entire natural plant communities in two Eastern Mediterranean sites. Additional sites along a natural rainfall gradient and selection analyses in a greenhouse assessed whether potential responses were adaptive. In both sites, our annual target species Biscutella didyma consistently evolved earlier phenology and higher reproductive allocation under drought. Multiple arguments suggest that this response was adaptive: it aligned with theory, corresponding trait shifts along the natural rainfall gradient, and selection analyses under differential watering in the greenhouse. However, another seven candidate traits did not evolve, and there was little support for evolution of plasticity. Our results provide compelling evidence for rapid adaptive evolution under climate change. Yet, several non‐evolving traits may indicate potential constraints to full adaptation.

Culshaw‐Maurer, Michael; Sih, Andrew; Rosenheim, Jay A.; Chase, Jonathan

doi: 10.1111/ele.13601pmid: 32902103

Enemy‐risk effects, often referred to as non‐consumptive effects (NCEs), are an important feature of predator–prey ecology, but their significance has had little impact on the conceptual underpinning or practice of biological control. We provide an overview of enemy‐risk effects in predator–prey interactions, discuss ways in which risk effects may impact biocontrol programs and suggest avenues for further integration of natural enemy ecology and integrated pest management. Enemy‐risk effects can have important influences on different stages of biological control programs, including natural enemy selection, efficacy testing and quantification of non‐target impacts. Enemy‐risk effects can also shape the interactions of biological control with other pest management practices. Biocontrol systems also provide community ecologists with some of the richest examples of behaviourally mediated trophic cascades and demonstrations of how enemy‐risk effects play out among species with no shared evolutionary history, important topics for invasion biology and conservation. We conclude that the longstanding use of ecological theory by biocontrol practitioners should be expanded to incorporate enemy‐risk effects, and that community ecologists will find many opportunities to study enemy‐risk effects in biocontrol settings.