BIO220H1 Lecture Notes - Lecture 1: Phenotypic Plasticity, Reaction Norm, Drug Resistance
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Where Phenotype comes from?
1. Genes, Environment and Behaviour
Evolutionary explanations for behaviours
2. The Evolution of Sexual Differences & Sexual Interactions
Sexual traits & behaviours
Thinking about evolutionary explanations for dramatic differences.
3. Cooperation & Conflict
Thinking about genes, rather than individuals.
Behaviours that potentially harm to the organism itself →conflict with evolution
Why organisms are in conflict?
4. Extended Phenotypes
Thinking about genes having effects outside of the organism that harbours those genes.
5. The Evolution of Disease
Applying evolutionary thinking to some of the most pressing problems of our time.
Drug resistance, virulence, emerging disease & vaccination
Vaccines: products of evolution
6. The Evolution of Senescence
Evolutionary explanations for non‐adaptive phenomena
Why hasn’t evolution rule it out?
Genes, Environment and Behaviour
• Genes and environment influence phenotypes including behaviours
• Natural selection shapes behaviours
Environmental effects on trait values can be described as “plasticity”; plasticity can be
adaptive (but isn’t always)
The influence of genes and environment can be visualized with plots of the “reaction
• Natural selection shapes the reaction norm (*visualize plasticity)
Two classes of scientific questions
• Why has that trait evolved? How/What?
How does an individual manage to carry out
• How do mechanisms
within an animal work to produce a p
ULTIMATE CAUSES PROXIMATE CAUSES
What is the causal relationship between the animal’s genes and its behaviour?
What genes are expressed?
Why has this behaviour evolved and how has it changed over evolutionary time?
What is the hormonal basis of infanticide?
Why has it evolved: what is the adaptive value of infanticide to both males and femal
Have you noticed that bees
and wasps behave oddly in
They are a little bit drunk
•What? Reaction to ethanol(easy to locate the fruit)
•How? Feeding on over ripe fruit (fruit fermentation)
•Why? An adaptation for locating ripened fruit
Drunk pollinators might be good for plants!
Produced alcohol →
Attract bees →
Drunk pollinators →
Might be an adaptive trait for the plant.
7. Genetic and environmental variation
• Same genetic make‐up
• Even slight differences in environment lead to variation in traits and behaviours
But, it’s difficult to conduct experiments on humans.
CAN do it on fruitflies!
Phenotypes reflect both genetic and environmental effects
GxE-gene by environment interaction
Impact of genetics might be dependent on environment