Premium
CONFLICTING SELECTION FROM AN ANTAGONIST AND A MUTUALIST ENHANCES PHENOTYPIC VARIATION IN A PLANT
Author(s) -
Siepielski Adam M.,
Benkman Craig W.
Publication year - 2010
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2009.00867.x
Subject(s) - biology , disruptive selection , selection (genetic algorithm) , variation (astronomy) , genetic variation , allee effect , ecology , stabilizing selection , evolutionary biology , phenotypic plasticity , directional selection , seed predation , seed dispersal , biological dispersal , natural selection , population , biochemistry , physics , demography , artificial intelligence , sociology , astrophysics , computer science , gene
The raw material for evolution is variation. Consequently, identifying the factors that generate, maintain, and erode phenotypic and genetic variation in ecologically important traits within and among populations is important. Although persistent directional or stabilizing selection can deplete variation, spatial variation in conflicting directional selection can enhance variation. Here, we present evidence that phenotypic variation in limber pine ( Pinus flexilis ) cone structure is enhanced by conflicting selection pressures exerted by its mutualistic seed disperser (Clark's nutcracker Nucifraga columbiana ) and an antagonistic seed predator (pine squirrel Tamiasciurus spp.). Phenotypic variation in cone structure was bimodal and about two times greater where both agents of selection co‐occurred than where one (the seed predator) was absent. Within the region where both agents of selection co‐occurred, bimodality in cone structure was pronounced where there appears to be a mosaic of habitats with some persistent habitats supporting only the seed disperser. These results indicate that conflicting selection stemming from spatial variation in community diversity can enhance phenotypic variation in ecologically important traits.