Two modes of host–enemy coevolution

Abstract

The process of coevolution between host and enemy has traditionally been viewed as an evolutionary arms race between resistance and counterresistance. The armsrace metaphor of coevolution is widely accepted because it explains the evolution of many characters in species involved in host-enemy interactions. However, molecular work in plant-pathogen systems suggests a coevolutionary interplay between plant recognition of an attacking pathogen and pathogen evasion from recognition. We refer to this process as information coevolution, and contrast this with arms race coevolution to show that these two processes result in very different patterns of host resistance and enemy virulence at the population level. First, information coevolution results in a lower proportion of hosts that are susceptible to enemy attack within a population. Second, information coevolution produces a pattern of local maladaptation of enemy on host, a naturally occurring phenomenon that is difficult to explain under arms race coevolution. We then conduct a literature review to survey the empirical support for either mode of coevolution using the predicted patterns of host resistance and enemy virulence. Evidence supports both modes of coevolution in plant-enemy interactions, whereas no support is found for information coevolution in vertebrate-parasite and invertebrate-parasite systems.

Re-imagining the growth process: (co)-evolving metaphorical representations of entrepreneurial growth

“…Simple examples include: the evolution of the beaks of hummingbirds and the shape of the flowers they feed on, the behaviour of bees and the distribution of flowering plants (Ehrlich and Raven 1964;Kniskern and Rausher 2001;Thompson 2005). A biological understanding of co-evolution is much more than a simple binary relationship between two parts of a wider a system but rather shows one species or population is necessary to the survival of other parts and integral component in a complex network of species in a richly connected web of life (Janzen 1980).…”

Population Dynamics, Demography, Dispersal and Spread of Bemisia tabaci

“…Furthermore, the apparent failure of many genetic groups to invade and establish in neighboring regions suggests that the capacity for B. tabaci to invade is uncommon. The failure of biotype B to establish permanently in southern Spain (Simon et al 1999) may indicate the difficulty of invading a neighboring territory because the populations have evolved the necessary characters to compete in response to interaction along the border (Kniskern and Rausher 2001). In contrast, species transplanted into a new geographic space may exhibit novel traits that confer a selective advantage against the indigenous population (Cox 2004).…”

Parasitic exploitation as an engine of diversity

“…In either case, each parasite genotype functions as either a resistance or a susceptibility allele, depending on the host genotype, and vice versa. Matching-alleles models do not require costs of resistance and virulence to explain the maintenance of high levels of polymorphism, because of the negative frequency-dependence inherent in these models (Kniskern & Rausher, 2001).…”

“…Hamilton, Axelrod & Tanese, 1990), whereas others have argued that there is an unlimited set of alleles that are continuously replaced (e.g. Kniskern & Rausher, 2001). It is possible that the number of available alleles in the set evolves.…”

“…Under local adaptation, local parasites are more effective than foreign parasites at exploiting local hosts, whereas under local maladaptation the reverse is true (i.e. transplantation experiments should demonstrate higher virulence of transplanted pathogens) (Kniskern & Rausher, 2001). …”