Evolution of Behaviour

Question 1

Behaviour can only evolve if..

Answer 1

• can only evolve if there is variation in the population
• transmission and from generation to generation

Question 2

What are the methods of studying genetics of behaviour?

Answer 2

*analysis of behavioural mutants
*cross-breeding experiments
*selective breeding

Question 3

Behaviour may evolve by

Answer 3

Cultural Evolution (some species) and Natural Selection (all species)

Question 4

What is a limitation to cultural evolution?

Answer 4

Cultural evolution occurs without a change in gene frequency

Question 5

What must occur for behaviour to evolve by natural selection?

Answer 5

For behaviour to evolve by natural selection, there must be variation in behaviour and in the genes for behaviour

Question 6

Co-adaptation

Answer 6

responses of individuals of a species are often adapted to each other, especially
* parent/offspring: e.g. feeding method of chick must be appropriate to method of food presentation by its parent
* male/female: e.g. releasers in male courtship and innate releasing mechanisms of female must be mutually adapted.

Question 7

What are the methods used to study the evolution of behaviour?

Answer 7

Genetic Analysis and Comparative approach

Question 8

Rituals

Answer 8

Complex behaviours that serve a communication function. They evolve through natural selection, starting from other behaviour patterns such as intention movements or displacement activities

Question 9

What are the two special cases of natural selection that apply to behviour?

Answer 9

Sexual selection and kin selection.

Question 10

Sexual Selection

Answer 10

Selection for ornaments and/or behaviours that contribute to reproductive success

Question 11

Altruism

Answer 11

Some animals display altruism, i.e. they act to increase another individual’s number of offspring at a cost to their own survival and reproduction

Question 12

Why did elaborate courtship displays and male ornaments evolve?

Answer 12

Darwin : elaborate courtship displays & male ornaments evolved due to selection pressure for reproductive success

*fight rivals and/or attract females
*contribute to reproductive success, but not survival

Question 13

Kin selection

Answer 13

the process by which characteristics are favoured due to their beneficial effects on the survival of close relatives including offspring and non-descendant kin

Question 14

Hamilton’s Rule

Answer 14

Altruistic behaviour will spread by kin selection when the benefits of helping outweigh the costs, i.e. if
rb-c > 0
(r= coefficient of relatedness, b and c are costs and benefits to helper);
a parent has an r of 0.5 with its offspring and with its siblings)

Question 15

Coefficient of relatedness “r”

Answer 15

is a measure of genetic similarity -
it is the probability that a gene in one individual is an identical copy, by descent, of a gene in another individual.

Question 16

Ritualisation

Answer 16

The term used to describe the evolution of elaborate displays through which animals communicate with each other is ritualisation

Question 17

intention movements

Answer 17

movements associated with take-off and attack

Question 18

Displacement Activities

Answer 18

seemingly irrelevant activities that occur at moments of balance between conflicting motivations such as aggression and sex

Question 19

Appeasement

Answer 19

actions that inhibit attack by another animal

Question 20

Autonomic Responses

Answer 20

Responses initiated by the autonomic nervous system under stress.

Question 21

What are the potential sources of info?

Answer 21

Intention Movements
Autonomic Responses
Displacement Activites

Question 22

Sexual Selection

Answer 22

Selection for ornaments and/or behaviours that contribute to reproductive success

Question 23

Frigate bird courtship display

Answer 23

Emotionally induced changes in breathing may have been the starting point for the evolution of the large inflatable throat sacs of the frigate bird used to attract females

Question 24

Threat display in gulls

Answer 24

Movements associated with takeoff and attack become incorporated into threat displays of gulls