Niche construction

What ways can behaviour affect evolution

• Driver of evolution

• Inhibitor of evolution

Rate of evolution

How does behaviour affect evolution?

Determines enviornment (habitat and social enviornment), mate choice, predator avoidance, competition

environmental change can affect evolution

Which sex exerts pressure for selective traits?

Females.

How does behaviour work as an inhibitor to evolution?

By shielding from environmental change

• move to less stressful environments

• reduce exposure to new selective pressure s

• evolutionary stasis

How to predators induce behaviour shifts ?

Anolis lizards (Bahamas)

• Predict that selection favours longer legged and larger A sagrei if its predators is present

• Or avoid selection and move up in the trees (no evolution)

• Habitat shift insufficient to prevent high mortality,

• positive selection on size and ling length

What are the requirements for behaviour to affect evolution?

1. Must occur in large enough sub-population so that selection finds enough variation to work on

2. Must persist over several generations

3. this must produce shift in other traits.

What do organisms constructing/modifying their environment change?

Selective pressure for themselves and others.

Is niche construction adaptation or extended phenotypes?

No but have major ecological and possibly evolutionary outcomes

what conditions do non-social ecological niches contain? non-social niche

Abiotic conditions and biotic conditions (heterospecific)

What conditions do a social niche (social ecological niche) include?

Biotic conditions - conspecific.

What is niche construction theory?

In many organisms, genes have an impact on the environment on which the animals are selected for and against

How have humans influenced biotic systems (historical human niche construction)

• Broad spectrum hunting and harvesting

• Landscape burning

• Habitat modification for agriculture, shelter

What is niche construction theory?

Process whereby organisms modify their own and each others niches

Changes may NOT JUST be adaptive and evolutionary consequences, but covers any changes over any timefrae

Emphasises how selection pressures are changes → hence niche construction is a separate evolutionary process to natural selection

Is environment a given external factor?

No, behaviour influences the direction of selection

Is niche selection a separate evolutionary process?

Debated