Evolution of camouflage drives rapid ecological change in an insect community.
BACKGROUND
Evolutionary change in individual species has been hypothesized to have far-reaching consequences for entire ecological communities, and such coupling of ecological and evolutionary dynamics ("eco-evolutionary dynamics") has been demonstrated for a variety systems. However, the general importance of evolutionary dynamics for ecological dynamics remains unclear. Here, we investigate how spatial patterns of local adaptation in the stick insect Timema cristinae, driven by the interaction between multiple evolutionary processes, structure metapopulations, communities, and multitrophic interactions.


RESULTS
Observations of a wild T. cristinae metapopulation show that locally imperfect camouflage reduces population size and that the effect of such maladaptation is comparable to the effects of more traditional ecological factors, including habitat patch size and host-plant species identity. Field manipulations of local adaptation and bird predation support the hypothesis that maladaptation reduces population size through an increase in bird predation. Furthermore, these field experiments show that maladaptation in T. cristinae and consequent increase in bird predation reduce the pooled abundance and species richness of the co-occurring arthropod community, and ultimately cascade to decrease herbivory on host plants. An eco-evolutionary model of the observational data demonstrates that the demographic cost of maladaptation decreases habitat patch occupancy by T. cristinae but enhances metapopulation-level adaptation.


CONCLUSIONS
The results demonstrate a pervasive effect of ongoing evolution in a spatial context on population and community dynamics. The eco-evolutionary model makes testable predictions about the influence of the spatial configuration of the patch network on metapopulation size and the spatial scale of adaptation.
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK; Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO 80309, USA. Electronic address: timothy.farkas@sheffield.ac.uk.
Timothy E
TE
Farkas
Tommi
T
Mononen
Aaron A
AA
Comeault
Ilkka
I
Hanski
Patrik
P
Nosil
D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D001717:Birds; D017753:Ecosystem; D051456:Gene Flow / Q000235:genetics; D005787:Gene Frequency / Q000235:genetics; D007313:Insecta / Q000235:genetics*; D008954:Models, Biological; D010858:Pigmentation / Q000235:genetics*; D011156:Population Density; D011158:Population Growth; D011235:Predatory Behavior; D012641:Selection, Genetic / Q000235:genetics*