The present is more important than the past: associations between
developmental stability, canalization and phenotypic plasticity in
response to heterogeneous experience
Abstract
The relationships among developmental stability, canalization and
phenotypic plasticity are not straightforward, but may be better
understood in the context of temporally heterogeneous environments. Our
objective was to investigate the effects of early experience with
temporally heterogeneous water availability on the associations between
developmental stability, canalization and phenotypic plasticity. We
subjected eight plant species to a first round of alternating inundation
and drought vs. constantly moderate water treatments and a second round
of water conditions. Fluctuating asymmetry (FA), intra- and
inter-individual variation (CVintra and CVinter), and plasticity in
traits were measured and correlations between variables were calculated
for each species. Early temporally heterogeneous experience decreased
the leaf size of half of the species, but had complex effects on leaf
fluctuating asymmetry (FA) and inter-individual variation (CVinter) in
traits immediately or in late conditions, with little effects on
intra-individual variation (CVintra). There were several positive
correlations between FA and CVinter, positive correlations between
CVinter and plasticity in early treatments, but negative correlations in
late treatments. Our results suggested complexity and variability in the
relationships between different mechanisms. Decreased canalization may
promote plastic responses in traits before or during the induction of
plasticity, whereas canalization may reflect phenotypic convergence
after plastic responses. Temporally heterogeneous experiences may
facilitate positive correlations or attenuate negative correlations
between decreased canalization and plasticity. We provide direct
evidence for relationships between developmental stability, canalization
and plasticity as well as the role of temporally heterogeneous
environments in modifying these processes. The integrative way that
plants deal with environmental variation demonstrates their ability to
evolve in multiple directions via many flexible adjustments in response
to varying environmental signals over a plant’s lifetime.