This blog post on ‘Adaptations to variable environments’ is part of the BES ‘Key Concepts in Ecology’ series, designed to help ecologists in learning the key topics in ecology! Take a look at the full series for a list of key topics you might typically find in an ecology textbook, each providing a quick introduction to the topic, and a list of suggested papers for students to refer to.  

We can all think of classic examples of adaptations to variable environments – think beak depth in Darwin’s finches in response to drought, for example. But since the pioneering work of Peter and Rosemary Grant, ecologists have learned so much more about how natural selection operates in the wild by studying adaptations to variable environments in a number of different systems. As an example that in some ways experimentally builds on the Grants’ work, Rodríguez-Alarcón et al. (2022) looked at how multiple plant traits among many species responded to drought. But climate change can also lead to phenological mismatches between, say, insectivorous birds and their prey, which in turn can affect individual fitness (e.g., Reed et al. 2013). While common garden experiments and reciprocal transplant gardens are the gold standard for detecting adaptations to different environments (Johnson et al. 2022), be they variable or otherwise, other approaches exist. For the past decade or so, trait-based ecological approaches, where essentially ecologists relate phenotypic traits to environment and infer process, have become increasingly common (e.g., Ding et al. 2013, Si et al. 2016, Si et al. 2017, Cadotte et al. 2019, Hagge et al. 2021). Still other approaches include linking theory, simulations, and data to understand the patterns and probabilities of selection in variable or rapidly changing environments (e.g., Hermisson and Pennings 2017). One classic approach has been to apply Optimal Foraging Theory to provide key insights into how (largely) animals acquire resources in variable environments (e.g. Jesmer et al. 2020, Smallegange and Van Der Meer 2003) or how resources (i.e., prey) avoid being eaten by multiple enemies (Üveges et al. 2021). Other work on resource acquisition by plants has focused on how, for example, mycorrhizal symbioses can facilitate resource acquisition in changing environments (e.g., Puy et al. 2022). But perhaps my favorite way that many plants and animals deal with variable, especially seasonal environments, is that they just go dormant (Wilsterman et al. 2021). 

Introduction written by Nate Sanders (Executive Editor, Journal of Animal Ecology). Reading list curated by the BES journal Editors. 

References and suggested reading 

Evolution of variable phenotypes  

• Reed, T.E. et al. (2013) Phenological mismatch strongly affects individual fitness but not population demography in a woodland passerine. Journal of Animal Ecology, 82: 131-144. 
  
• Johnson, L. C. et al. (2022) Reciprocal transplant gardens as gold standard to detect local adaptation in grassland species: New opportunities moving into the 21st century. Journal of Ecology, 110: 1054–1071. 
  
• Hermisson, J. et al. (2017) Soft sweeps and beyond: understanding the patterns and probabilities of selection footprints under rapid adaptation. Methods in Ecology and Evolution, 8: 700-716. 

Traits to deal with enemies  

• Üveges, B. et al.  (2021) Chemical defence effective against multiple enemies: Does the response to conspecifics alleviate the response to predators? Functional Ecology, 35: 2294–2304. 

Traits to deal with variable abiotic environment  

• Rodríguez-Alarcón, S. et al. (2022) Intraspecific trait changes in response to drought lead to trait convergence between—but not within—species. Functional Ecology, 36: 1900–1911. 
  
• Puy, J. et al. (2022) Mycorrhizal symbiosis alleviates plant water deficit within and across generations via phenotypic plasticity. Journal of Ecology, 110: 262–276. 

Migration, storage, and dormancy  

• Wilsterman K. et al (2021) A unifying, eco-physiological framework for animal dormancy. Functional Ecology, 35: 11–31. 

Optimal foraging theory  

• Jesmer B.R. et al. (2020) A test of the Niche Variation Hypothesis in a ruminant herbivore. Journal of Animal Ecology, 89: 2825–2839. 
  
• Smallegange I.M. et al. (2003) Why do shore crabs not prefer the most profitable mussels? Journal of Animal Ecology, 72: 599-607. 

Trait-based ecology  

• Hagge J. et al. (2021) What does a threatened saproxylic beetle look like? Modelling extinction risk using a new morphological trait database.Journal of Animal Ecology, 90: 1934–1947. 
  
• Si X. et al. (2016) Selective extinction drives taxonomic and functional alpha and beta diversities in island bird assemblages. Journal of Animal Ecology, 85: 409-418. 
  
• Si X. et al. (2017) Functional and phylogenetic structure of island bird communities. Journal of Animal Ecology, 86: 532-542. 
  
• Ding Z. et al. (2013) Patterns of bird functional diversity on land-bridge island fragments. Journal of Animal Ecology, 82: 781-790. 
  
• Cadotte M.W. et al. (2019) Do traits and phylogeny support congruent community diversity patterns and assembly inferences? Journla of Ecology, 107: 2065–2077.