Midterm 1 3T03

Character Displacement

Divergence in traits caused by competition between species where differences become exaggerated

Character release

In the absence of competition, there is a greater overlap in traits than when both species are found are found together

Profitability equation

Energy / Handling time

When to choose one prey over another (eq)

E1/H1 > E2/H2

When to eat prey 2

E2/H2 > E1 / (S1+H1)

Generalists wrt S and H

Prefer short S and H

Specialists wrt S and H

Long S and H

How to increase Search Tiem?

Camouflage/Crypsis and polymorphism

How to increase handling time

Anti-predator defends and toxins

Nash equilibrium

No player has incentives to change strategies based on what others are doing

3 pillars of ecology

Levels of analysis, optimality and game theory

Primary, Secondary and tertiary sex ratio

Primary=at conception, 2=at birth, 3=at sexual maturity

Maternal sex ratio (distorter)

Fertilize all eggs = 100% daughters

Son killer (distorter)

Bacteria kills unfertilized eggs so no sons produced

Paternal sex ratio (distorter)

Convert fertilized haploid eggs into haploid = 100% sons

Wollacia (distorter)

Bacteria feminized makes, inducing parthenogenesis and sperm incompetency

How do bird manipulate sex ratios?

Maternal stress hormone levels

How do mammals manipulate sex ratios? 2

Maternal testosterone hypothesis (more T= more male offspring)

Good condition hypothesis: maternal glucose levels post-conception and dietary fat (high fat & glucose = more males)