Data from: Maladapted prey subsidize predators and facilitate range expansion

Dispersal of prey from predator-free patches frequently supplies a trophic
subsidy to predators by providing more prey than are produced locally.
Prey arriving from predator-free patches might also have evolved weaker
defenses against predators and thus enhance trophic subsidies by providing
easily captured prey. Using local models assuming a linear or accelerating
tradeoff between defense and population growth rate, we demonstrate that
immigration of undefended prey increased predator abundances and decreased
defended prey through eco-evolutionary apparent competition. In
individual-based models with spatial structure, explicit genetics, and
gene flow along an environmental gradient, prey became maladapted to
predators at the predator’s range edge, and greater gene flow enhanced
this maladaptation. The predator gained a subsidy from these easily
captured prey, which enhanced its abundance, facilitated it's
persistence in marginal habitats, extended its range extent, and enhanced
range shifts during environmental changes, such as climate change. Once
the predator expanded, prey adapted to it, and the advantage disappeared,
resulting in an elastic predator range margin driven by eco-evolutionary
dynamics. Overall, the results indicate a need to consider gene
flow-induced maladaptation and species interactions as mutual forces that
frequently determine ecological and evolutionary dynamics and patterns in
nature.