1/23/2017
Reaction Norms
• Change in phenotype (or genotype) over a range of levels
for one environmental variable (adaptagent).
Plasticity, canalization and adaptation
• Types of norms
– Graded
– Canalized
– Polymorphism
Spike Length
Polymorphism example
Concentration of Fish Cues
Remember – reaction norms can apply to morphology, behavior, physiological traits etc.
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1/23/2017
Homeostasis
External vs. Internal conditions
• Regulation of internal body conditions
• Often regulated via negative feedback system
Thermostat
Input feedback
Furnace
Air
Conditioner
• Three general types of managing internal conditions
– Avoiders
– Conformers
– Regulators
• Prefix: Homeo or poikilo
• Suffix: thermo, haline etc…
Internal Environment
Hot or cold air
External Environment
Avoiders, Conformers and Regulators
Various methods for regulating, conforming or avoiding
Icefish:
Stenothermal or eurythermal?
Oligothermal or polythermal?
Homeothermic or poikilothermic?
Ectothermic or endothermic?
Avoider, conformer or regulator?
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1/23/2017
Mechanisms of Adaptation
+ environment =
• DNA – genotype
• Phenotype – what
selection acts on.
• Review basics of protein
synthesis.
• Genes are expressed to
produce proteins. Proteins
perform most functions,
make up what the
phenotype is.
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