L6 - Predation

Question 1

What is absolute fitness?

Answer 1

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

Question 2

What does absolute fitness depend on?

Answer 2

• Viability
• Reproductive success

Question 3

What is relative fitness?

Answer 3

The absolute fitness divided by the mean fitness of that population

Question 4

What is the gain/ loss for each organism involved in mutualism?

Answer 4

Both gain

Question 5

What is the gain/ loss for each organism involved in competition?

Answer 5

Both lose

Question 6

What is the gain/ loss for each organism involved in commensalism?

Answer 6

One gains, one does not gain or lose

Question 7

What is the gain/ loss for each organism involved in predation?

Answer 7

One gains, one loses

Question 8

What is crypsis?

Answer 8

The ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle and mimicry.

Question 9

What is an example of how crypsis can help animals avoid predation?

Answer 9

The changes in the populations of the peppered moth during the Industrial Revolution -
The typical peppered moth survived well in places that did not see major effects of the industrial evolution as its camouflage still worked. The fully black peppered moth survived well in places that saw major effects of the industrial evolution, they were able to camouflage as the air quality had led to buildings/ trees becoming black

Question 10

Give a example of when crypsis included behavioural components

Answer 10

With the Catocala cerogama - this moth nearly always rests on a tree with either its head up or down. Study was done which showed that when it rested with it’s head up or down it was much harder to see, therefore more likely to avoid predation

Question 11

What is the aim of crypsis?

Answer 11

Organisms attempt to avoid being noticed.

Question 12

What is masquerade?

Answer 12

When organisms attempt to be mistaken for non-prey.

Question 13

What part of the predator does crypsis exploit?

Answer 13

Exploits predator sensory limitations

Question 14

What part of the predator does masquerade exploit?

Answer 14

Exploits predator cognitive limitations

Question 15

Give an example of an animal using masquerade

Answer 15

The giant swallowtail butterfly - the lava looks like bird poo

Question 16

Give an example of when using masquerade require behavioural components

Answer 16

Cuttlefish - imitates the plants objects around it

Question 17

What is aposematism?

Answer 17

The advertising by an animal to potential predators that it is not worth attacking or eating

Question 18

What does the effect of aposematism (on the animal showing aposematism) depend on? Give example

Answer 18

Density - with spotted bird grasshoppers. Only when raised with high density/ population of other do grasshoppers they show aposematism. When raised in low density environment they camouflage. This works because predator will be more likely to eaten and not liked taste of grasshopper if there are more so worth showing it is a grasshopper

Question 19

What does aposematism provide models for? Give example

Answer 19

Mimicry - milk snake mimics eastern coral snake, appears venomous

Question 20

What is Bayesian mimicry?

Answer 20

A form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both

Question 21

What is mullein mimicry?

Answer 21

A natural phenomenon in which two or more well-defended species (often foul-tasting and sharing common predators) have come to mimic each other’s honest warning signals, to their mutual benefit.