bi303 phenotypic plasticity

phenotypic plasticity

genetically encoded flexibility

ability of a single genotype to produce multiple phenotypes irt environmental conditions

powered by regulatory genes that ‘switch on’ structural genes

• acclimation - individual shift in range of physiological tolerance - REVERSIBLE

• developmental response - change in environment influences individual development - NOT REVERSIBLE

reaction norm

set of one genotype’s possible phenotypes

example - alaska vs michigan swallowtail caterpillars

AK - always cold, less change, loses plasticity. less steep rxn norm
MI - more temp variation, more change, keeps plasticity. steeper rxn norm

reaction norm framework

genetic variation vs plasticity

dogwinkle snail case study

control, crab eating fish, crab eating snail

control - normal shell

crab eating fish - thicker shell

crab eating snail - thickest shell

responds in shell thickness. yes, visible plasticity/response to environment

case study - why not always have thick shells?

ENERGY WASTE - the more energy given to grow shell, the lesser the body weight