… Mutualisms can be markedly dynamic at both ecological and evolutionary time scales, shifting
along a natural continuum … general directional evolutionary shifts based on mutualism type…

… mutualist continuum. In this Review, we integrate theoretical and empirical findings to discuss
the mechanisms underpinning these evolutionary shifts… end of the continuum. In addition to …

… shift in the frequency of genetic variants, coupled with major changes in gene expression,
allow the symbiont to alter its position in the parasitism–mutualism continuum … or mutualistic …

… Thus, while facultative mutualisms form a continuum in terms of dependence, obligate
ones … other pathways of mutualism breakdown, notably extinction and shifting to parasitism. …

… understanding of the evolutionary and ecological processes that shape mutualism. Species
… be sufficient to trigger the breakdown of mutualism and an evolutionary shift to parasitism. …

… mutualism and facilitation. Five focal areas organize current research on mutualism evolution:
trait evolution; the continuum … been under selection to produce such shifts are not yet well …

… The ready transitions across this parasite–mutualism continuum in experimental evolution
and in clinical microbes suggest that evolutionary conflict between hosts and symbionts is real …

… , whether mutualisms … non-mutualist) taxa are nested within ancestrally mutualistic clades.
Although models have focused on the propensity of mutualism to become parasitic, such shifts …

… For example, a microbe acting as a commensal or mutualistic organism may shift to a
pathogenic role to overcome immediate challenges to meet demands for growth and activity (Fig. …

… insect–plant mutualisms are identified and their evolutionary … the existence of a continuum
from specialization to generalization… Evolutionary shifts can also be identified in flower-visiting …