Emergence of a novel prey life history promotes contemporary sympatric diversification in a top predator

Abstract

Intraspecific phenotypic variation can strongly impact community and ecosystem dynamics. Effects of intraspecific variation in keystone species have been shown to propagate down through the food web by altering the adaptive landscape for other species and creating a cascade of ecological and evolutionary change. However, similar bottom-up eco-evolutionary effects are poorly described. Here we show that life history diversification in a keystone prey species, the alewife (Alosa pseudoharengus), propagates up through the food web to promote phenotypic diversification in its native top predator, the chain pickerel (Esox niger), on contemporary timescales. The landlocking of alewife by human dam construction has repeatedly created a stable open water prey resource, novel to coastal lakes, that has promoted the parallel emergence of a habitat polymorphism in chain pickerel. Understanding how strong interactions propagate through food webs to influence diversification across multiple trophic levels is critical to understand eco-evolutionary interactions in complex natural ecosystems.

A way forward with eco evo devo: an extended theory of resource polymorphism with postglacial fishes as model systems

“…Furthermore, phenotypic divergence of the focal fish can have a bottom-up effect on the morphology (e.g. chain pickerel, Esox niger; Brodersen, Howeth, & Post, 2015) or trophic position (e.g. brown trout, Salmo trutta; Thomas et al, 2017) of their predators -which again can feed back as altered predation pressure.…”

Feedbacks link ecosystem ecology and evolution across spatial and temporal scales: Empirical evidence and future directions

“…Year‐round predation reduces zooplankton body size, thereby creating an eco‐evo feedback that selects for smaller alewife gape and gill raker spacing (Palkovacs & Post, ). The ecological effects of alewife divergence also have impacts on the evolution of alewife prey (Walsh & Post, ), competitors (Huss, Howeth, Osterman, & Post, ) and predators (Brodersen, Howeth, & Post, ). In guppy populations, fish predators increase mortality rates and decrease guppy densities (Figure : FB1a ; Reznick, Bryga, & Endler, ; Reznick, Butler, Rodd, & Ross, ).…”

“…The ecological effects of alewife divergence also have impacts on the evolution of alewife prey (Walsh & Post, 2011), competitors (Huss, Howeth, Osterman, & Post, 2014) and predators (Brodersen, Howeth, & Post, 2015). In guppy populations, fish predators increase mortality rates and decrease guppy densities Reznick et al, 1990;Reznick et al, 1996, Palkovacs et al, 2011Zandonà et al, 2011;FB1b: Palkovacs et al, 2009;Bassar et al, 2010;Bassar et al, 2013;FB2: El-Sabaawi et al, 2015) size at maturity (Bassar, Lopez-Sepulcre, Reznick, & Travis, 2013).…”

Partial nomadism in large‐bodied bream (Abramis brama)

“…Animal movement between ecosystems often occurs in predictable rhythmic patterns (Chapman et al, ; Dingle & Drake, ). Such migratory movements are key events in many individual life histories and can have large effects on ecosystems (Bauer & Hoye, ; Brodersen, Howeth, & Post, ; Brodersen et al, ; Post, Palkovacs, Schielke, & Dodson, ). Individual movements between ecosystems can also occur in more variable arrhythmic manner (Jonzén, Knudsen, Holt, & Sæther, ), and such dispersal‐like movements are cornerstones in metacommunity and metapopulation theory (Hanski, ; Leibold et al, ).…”