The Selection Mosaic and Diversifying Coevolution between Crossbills and Lodgepole Pine
- 1 May 1999
- journal article
- research article
- Published by University of Chicago Press in The American Naturalist
- Vol. 153 (S5), S75-S91
- https://doi.org/10.1086/303213
Abstract
Asymmetrical competition determines which of two seed predators drives the evolution of lodgepole pine (Pinus contorta ssp. latifolia) cones. Red squirrels (Tamiasciurus hudsonicus) are effective preemptive competitors in lodgepole pine forests so that red crossbills (Loxia curvirostra) are uncommon and selection from Tamiasciurus drives cone evolution. When Tamiasciurus are absent, crossbills increase in abundance and coevolve in an evolutionary arms race with pine. Similarly, Tamiasciurus alters the evolutionary trajectories of large‐seeded pines, many of which rely on birds (Corvidae) for their seed dispersal. Populations therefore exhibit a selection mosaic with coevolutionary hot spots. In the coevolutionary hot spots, divergent selection on crossbills potentially leads to reproductive isolation and speciation. This results in a subsequent reduction in the geographic mosaic but diversifies the adaptive landscape on which crossbills have radiated. Thus, divergent selection is a double‐edged sword. Divergent selection is critical in creating a selection mosaic but erodes the selection mosaic when it promotes reproductive isolation and speciation.Keywords
This publication has 65 references indexed in Scilit:
- WHEN IS BIOLOGICAL CONTROL EVOLUTIONARILY STABLE (OR IS IT)?Ecology, 1997
- Heat budget and fire behaviour associated with the opening of serotinous cones in two Pinus speciesJournal of Vegetation Science, 1993
- Character displacement and replicate adaptive radiationTrends in Ecology & Evolution, 1993
- Evolution of Darwin’s finches caused by a rare climatic eventProceedings Of The Royal Society B-Biological Sciences, 1993
- Red Squirrel Population Dynamics I. The Effect of Supplemental Food on DemographyJournal of Animal Ecology, 1991
- Responses of Red Squirrel (Tamiasciurus hudsonicus) Populations to Supplemental FoodJournal of Mammalogy, 1990
- The effects of stand density on frequency of filled seeds and fecundity in lodgepole pine (Pinuscontorta Dougl.)Canadian Journal of Forest Research, 1988
- Foraging Behavior of a Central-Place Forager: Field Tests of Theoretical PredictionsThe American Naturalist, 1988
- The Pinus Contorta Forests of Banff and Jasper National Parks: A Study in Comparative Synecology and SyntaxonomyEcological Monographs, 1980
- The late-Quaternary vegetational history of the Western Interior of CanadaCanadian Journal of Botany, 1976