Chapter 2 - Evolution and Behaviour: Natural Selection

Question 1

Why is learning so important? and how do we learn?

Answer 1

learning is important because it allows organisms to adapt to new environments that can easily change

animals adapt to changing environments through experiences

learning happens through experience

Question 2

What is the driving force of evolution?

Answer 2

the driving force of evolution is reproduction; if one cannot reproduce, then natural selection can’t act on anything

Question 3

What is the main criteria for evolution?

Answer 3

fitness is the main criteria for evolution

being ‘fit’ means being able to pass genes onto the next generation

Question 4

What is natural selection?

Answer 4

natural selection involves the increase likelihood of reproduction in individuals with adaptive traits and the representation of those traits in future generations

natural selection is a consequence of being well-adapted

Question 5

what are the three ways that behaviour can evolve through natural selection?

Answer 5

1. there is variation in behaviour
2. that variation is linked to a gene and is heritable (passed down)
3. That behaviour leads to an adaptive advantage

Question 6

What is ethology?

Answer 6

The study of the evolution of behaviour

behaviour can not be studied directly from the past so there has to be indirect methods to study it

Question 7

What are 2 indirect methods of studying behaviour?

Answer 7

1) study behaviours of related species
2) evaluative approach ==> evaluating the possible benefit or survival value of the behaviour; this works best with direct evidence to support hypothesized benefit

Question 8

What was the Niko Tinbergen experiment w/ black-headed gulls?

Answer 8

Black headed gulls fly distances away with bird shells of their young after a couple of hours after when they are hatched (sometimes within minutes); Tinbergen hypothesized that the bright white lining of the shell would make the nest easier to detect by predators.

Tinbergen did an experiment where he took the shells of the black headed gull and placed them about four inches away from the nest where the eggs were and discovered that the shells were discovered more than the egg itself

Further experiments showed that the farther from an intact egg the eggshell was placed, the safer the intact egg. Tinbergens experiments with black-headed gulls reinforced the idea that eggshell removal improved protection from predators

Question 9

What are two ways researchers can go about to understand how behaviours have adapted to the environment?

Answer 9

1. study related animals in different environments (e.g. black-headed gulls and kittiwakes) where kittiwakes live in high altitudes and have less predators therefore they do not practice the shell removing method
2. Study unrelated animals in similar environments and see iff they have the same behaviours (convergent evolution)

Question 10

What is convergent evolution?

Answer 10

its independant evolution of similar features in species of similar lineages/environments; i.e. flying/wings developing in bats vs. in birds

Question 11

What are Fixed Action Patterns proposed by Konrad Lorenz?

Answer 11

they are fixed behaviour sequences that are triggered by stimuli called releasers or SIGN STIMULI

these fixed behaviour sequences are highly stereotyped (looks the same every time it happens across organisms)

fixed action patterns do not depend on learning or experience and appear to be innate/genetic

after initial triggering of the fixed action pattern, the sequence will continue regardless of interruptions and does NOT depend on feedback (animal will keep doing this until its done)

Question 12

Describe the example of three-spines sticklebacks and fixed action patterns

Answer 12

territorial males of the three-spines stickleback attack any type of ‘fish’ that has a red under belly. Even when its replaced with a dummy that doesn’t even look like a fish but has a red belly, they attack. Regardless of whether or not the fish responds

Question 13

What are two experiments one can do to show that a behaviour is innate?

Answer 13

1. Deprivation experiments

2. Artificial Selection experiments

Question 14

What are deprivation experiments?

Answer 14

removing environmental stimuli and seeing if the behaviour still occurs; its tricky because you can’t remove ALL environmental stimuli

Question 15

What are artificial selection experiments?

Answer 15

an experiment based off the idea that if a gene linked to a trait has a strong genetic component then the offspring of the animal should also have that trait

Question 16

What is an example of how innate behaviour can be modified by experience through classical conditioning?

Answer 16

pairing a stimulus with a response

An example of this would be to pair a light before a sickleback is exposed to a red-bottom predator; so 
US: red-bottom rival
UR: attack rival (innate)/aggression
CS: light
CR: attack rival / aggression

so then sicklback will associate the light with the appearance of the rival and begin to show aggression when exposed to the light

Question 17

What is an example of how innate behaviour can be modified by experience through operant conditioning?

Answer 17

pairing a behaviour with a biologically relevant response

i.e. Herring-gull chicks will peck at a red dot on the mother’s beak which makes the moms regurgitate food; the more far away from the centre of the red dot they peck at it, the slower they get food; until they learn to peck right on the centre of the red dot

Question 18

How does habituation occur towards an innate behaviour?

Answer 18

Habitutaion has food implications; people with higher BMI’s habituate to the taste of food slower than people who have lower BMI’s; this means they still get the pleasure of the taste of the food for longer periods of time before they ‘stop tasting it’

Question 19

Why are innate behaviours beneficial?

Answer 19

beneficial upon first encounter with a stimulus that is dangerous or harmful like a predator

Question 20

____ allows behaviours to adapt over generations to changing environments

Answer 20

evolution

Question 21

_____ allows behaviours to adapt over lifespan of an animal to changing environments

Answer 21

learning

Question 22

How does operant (R-O) conditioning help in adaptation?

Answer 22

R-O –> increases behaviours that increase fitness (i.e. access to food, water, copulations, and increase survival and reproductive success

i.e. parents and babies –> both reinforced by social stimuli such as smiling to get things that need to ‘be fit’

another example is how Crows know the optimal height to feed on whelks