TITLE:
The ecological context of bilateral symmetry of organ and organisms
AUTHORS:
Danilo M. Daloso
KEYWORDS:
Bilateral Symmetry; Fluctuating Asymmetry; Stress; Phenotypic Plasticity; Developmental Stability
JOURNAL NAME:
Natural Science,
Vol.6 No.4,
February
27,
2014
ABSTRACT: A particular phenotype is generated through numerous
networks of interactions from within the cell to the whole ecosystem. The level of the environmental noise and the ability of a
given genotype to render different phenotypes under different environmental
conditions, called phenotypic plasticity, determine
survival or death at individual and/or population level. It is important to highlight
that non-lethal environmental changes are important for generating genetic
variability and promoting biological adaptations. However, when the level of
environmental noise starts to be stressed, the developmental stability (DS) of the organism can be perturbed. The DS has been analysed through the symmetry deviations in organs or organisms with
bilateral structure. The symmetry deviations occur due to inability to contain
disorders from environmental or endogenous conditions during its development.
This deviation is called fluctuating
asymmetry (FA) when is a non-directional deviation in the symmetry of a
bilateral structure normally distributed in a population. Low FA has
been associated with greater DS. The analysis of FA has often been used to
measure the effects of environmental perturbations. In this review, I discuss
the concept of plant stress and phenotypic plasticity connecting both to the generation of an asymmetry phenotype,
highlighting the usefulness of FA as an indicator of the level of stress which
the organism is subjected to. Further, although this review explores mainly the
connection between FA and stress in plants, the ecological context of
symmetry in animals and plant-insect interaction is also discussed. Finally, I
provided some methodologies used to detect symmetry variations in organs or organisms
with bilateral structure.