Predation

What is absolute fitness?

The expected number of offspring that an individual will produce over the course of its liftime

What does absolute fitness depend on?

• Viability

• Reproductive success

What is relative fitness?

The total number of offspring an organism has compared to the average number of offspring for the population

What can you calculate from the relative fitness?

Whether phenotype will increase or decrease in the next generation

What are the different types of relationships between organisms that can have fitness effects?

• Mutualism

• Competition

• Commensalism

• Predation

What can cryptos help animals avoid?

Predation

What did the great smog of London show?

Predation had the impact on surviving moths.

What can crypsis include?

Behavioural components

What was the behavioural element to crypsis?

Proportion of moths surviving predation differed based on orientation

Which orientation did more moths survive?

Vertical orientation in catocala, not euphyia.

What is crypsis? What does it exploit?

organisms attempt to avoid being noticed. exploits predator sensory limitations.

What is masquerade? What does it exploit?

Organisms attempt to be mistaken for non-prey. Exploits predator cognitive limitations

How can masquerade be behaviour?

Changing colour or shape

• E.g. cephalopod

How can prey deter predators with colour?

Aposematism

Give examples of animals that do aposematism?

• Monarch butterfly

• Crawl snake

• Poisonous frog

• Bee/wasp

What is aposematism?

Advertise a toxic trait that will kill a predator

How Is aposematism costly?

• Costly to produce toxins

What does the spotted bird grasshopper show about aposematism?

• When raised in high density - develops warning colours. Most predators know not to eat

• When rare, predators may attack so better to be camouflaged

What does aposematism provide models for ?

Mimicry

Who does aposematism cause costs for?

Costs to crawl snake which is actually poisonous, but milk snake isnt’.

What are the two types of mimicry?

Batesian and mullerian

What is the difference between Batesian and mullerian mimicry?

• Batesion - harmless species copies harmful species

• Mullerian - multiple dangerous species evolve to resemble each other, creating shared warning signal

  • e.g. butterflies and wasps

What does the case study of the matador bug show?

Predator deception

• Plates on leg

• Deflection

• Wave legs in presence of predator - predator attacks legs so bug survives