Advanced Behavioural and Evolutionary Ecology

Introduction + Adaptation, fitness selection

What are 4 key concepts in behavioural ecology?

Comparative approach, Kin selection, Optimality approach, Frequency dependence and evolutoinary stable strategies (game theory approach)

Describe comparative approach

Relating differences in behaviour between related species to differences in ecological conditions

Describe kin selection

A behaviour will be selected for or against because of the effects on an individual’s fitness and the fitness of relatives

Describe optimality approach

Selection optimises the spread an individual’s genes by weighing the costs and benefits associated with a specific behaviour

Describes the game theory appraoch

The costs or benefits of a behaviour will depend on what other individuals in the population are doing

Give an example of the comparative approach

Differences in social organisation in African ungulates reflecting dietary requirements depending on body size. From solitary foragers (quality food) to large-group living species eating low quality food

Give an example of kin selection

Sentinels in ground squirrels are subject to a higher predation risk but help related individuals by warning of predators

Give example of optimality approach

Starling optimise feeding rate at nest. Decision based on how many prey items to take per round depending on travel and search time

Game theory approach, give exapmle

Competing male dungflies maximising copulation rate by waiting for varying lengths of times at cow pats for arriving females

Why do evolutionary biologists emphasise natural selection in generating adaptation to local environments?

• reciprocal transplants

  • residents locally adapted compared to non residents

• Most phenotypes close to adaptive peaks

• Natural populations have high levels of additive genetic variance in traits (adaptation can be quick)

• Populations show rapid adaptations

Why do ecologists emphasise imperfections of adaptation to local environments?

• declining populations but locally well adapted

• contracting ranges

• local extinctions

How does the focus of evolutionary biologists differ from ecologists?

• Evo bio - focus on relative fitness, maladaptation lowers individual relative fitness

• Ecologists - focus on absolute fitness - growing pop (good adaptation) decreasing (maladaptation)

What is the working fitness definition?

‘ a measurable feature of alleles, genotypes of traits of individuals predictive of their future numerical representation ‘