A geographic mosaic of trophic interactions and selection: Trees, aphids and birds

D. S. Smith, J. K. Bailey, Stephen M Shuster, Thomas G Whitham

Research output: Contribution to journalArticle

28 Scopus citations


Genetic variation in plants is known to influence arthropod assemblages and species interactions. However, these influences may be contingent upon local environmental conditions. Here, we examine how plant genotype-based trophic interactions and patterns of natural selection change across environments. Studying the cottonwood tree, Populus angustifolia, the galling aphid, Pemphigus betae and its avian predators, we used three common gardens across an environmental gradient to examine the effects of plant genotype on gall abundance, gall size, aphid fecundity and predation rate on galls. Three patterns emerged: (i) plant genotype explained variation in gall abundance and predation, (ii) G×E explained variation in aphid fecundity, and environment explained variation in gall abundance and gall size, (iii) natural selection on gall size changed from directional to stabilizing across environments.

Original languageEnglish (US)
Pages (from-to)422-429
Number of pages8
JournalJournal of Evolutionary Biology
Issue number2
StatePublished - Feb 2011



  • Community genetics
  • Cottonwood
  • Genes to ecosystem
  • Geographic mosaic
  • Populus
  • Predator/prey
  • Selection
  • Trophic interactions

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this