Many mutualistic interactions are probably not mutualistic across all populations and years. This article explores consequences of this observation with a series of genetic models that consider how variable mutualisms coevolve. The first models, previously introduced in a general coevolutionary context, consider two coevolving species whose fitness interactions change between beneficial and ant...

The adaptive value of acarinaria - specialized structures in some wasps and bees that harbour symbiotic mites - has long been elusive. A new study has now shown that the mites are actually beneficial to their host by actively defending it against parasitoids.

Conditions are analyzed under which natural selection favors an individual to help another species at a cost to its own reproduction. Traditional models for the evolution of altruism between species focus on the genetic relatedness between the original donor and the recipients of return benefits from the mutualistic partner species. A more general model is analyzed here that focuses on the syne...

⁎ Corresponding author. 10 Sachem Street, New Have E-mail address: [email protected] (B.M. Wood). http://dx.doi.org/10.1016/j.evolhumbehav.2014.07.007 1090-5138/© 2014 Elsevier Inc. All rights reserved. Please cite this article as: Wood, B.M., et al. (2014), http://dx.doi.org/10.1016/j.evolhum Article history: Initial receipt 16 December 2013 Final revision received 21 July 2014 Available onl...

Current competition theory does not adequately address the fact that competitors may affect the survival, growth, and reproductive rates of their resources. Ecologically important interactions in which consumers affect resource vital rates range from parasitism and herbivory to mutualism. We present a general model of competition that explicitly includes consumer-dependent resource vital rates....

Mutualisms are widespread, yet their evolution has received less theoretical attention than within-species social behaviors. Here, we extend previous models of unconditional pairwise interspecies social behavior, to consider selection for donation but also for donation-suppressing modifiers. We present conditions under which modifiers that suppress costly donation receive either positive or neg...

Altruism presents a challenge to evolutionary theory because selection should favor selfish over caring strategies. Greenbeard altruism resolves this paradox by allowing cooperators to identify individuals carrying similar alleles producing a form of genic selection. In side-blotched lizards, genetically similar but unrelated blue male morphs settle on adjacent territories and cooperate. Here w...

Phenotypic plasticity describes the capacity of a genotype to exhibit a range of phenotypes in response to variation in the environment. Environmental variation encompasses both abiotic and biotic components of the environment, including interactions among organisms. The strength and outcome of many ecological interactions, ranging from antagonism to mutualism, are mediated through the phenotyp...