Using ecological context to interpret spatiotemporal variation in natural selection

Research output: Contribution to journalArticle

Abstract

Spatiotemporal variation in natural selection is expected, but difficult to estimate. Pollinator-mediated selection on floral traits provides a good system for understanding and linking variation in selection to differences in ecological context. We studied pollinator-mediated selection in five populations of Dalechampia scandens (Euphorbiaceae) in Costa Rica and Mexico. Using a nonlinear path-analytical approach, we assessed several functional components of selection, and linked variation in pollinator-mediated selection across time and space to variation in pollinator assemblages. After correcting for estimation error, we detected moderate variation in net selection on two out of four blossom traits. Both the opportunity for selection and the mean strength of selection decreased with increasing reliability of cross-pollination. Selection for pollinator attraction was consistently positive and stronger on advertisement than reward traits. Selection on traits affecting pollen transfer from the pollinator to the stigmas was strong only when cross-pollination was unreliable and there was a mismatch between pollinator and blossom size. These results illustrate how consideration of trait function and ecological context can facilitate both the detection and the causal understanding of spatiotemporal variation in natural selection.

Details

Authors
  • Elena Albertsen
  • Øystein H. Opedal
  • Geir H. Bolstad
  • Rocío Pérez-Barrales
  • Thomas F. Hansen
  • Christophe Pélabon
  • W. Scott Armbruster
Organisations
External organisations
  • Norwegian University of Science and Technology
  • Norwegian Institute for Nature Research
  • University of Portsmouth
  • University of Oslo
  • University of Alaska Fairbanks
  • Norwegian Institute of Bioeconomy Research (Nibio)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Evolutionary Biology

Keywords

  • Dalechampia scandens, path analysis, phenotypic selection, plant-pollinator interaction, pollen limitation, spatial variation, temporal variation
Original languageEnglish
JournalEvolution
Publication statusE-pub ahead of print - 2020 Nov 23
Publication categoryResearch
Peer-reviewedYes