Cooperation 1

Question 1

Historical puzzle of cooperation

Answer 1

Darwin clearly recognised the problem that cooperation poses for his theory of evolution by natural selection.

Natural selection favours the individuals who have the greatest personal reproductive success.

It is unclear why an organism should be selected to enhance the fitness of another.

Question 2

Darwin’s explanation of cooperation?

Answer 2

With social insects, selection has applied to the family, not individual

Indirect fitness benefit, or an increase in the reproductive success of relatives who share genes in common with the actor

Question 3

How is cooperation defined?

Answer 3

Any behaviour that increases the fitness of the recipient (mutual benefit and altruism)
Based on total lifetime fitness effects
Complicated link between social behaviours and total fitness effects

Question 4

What is altruism?

Answer 4

Negative effect on actor’s fitness. Positive effect on recipients fitness

Question 5

Describe the theory of cooperation

Answer 5

Bill Hamilton

Inclusive fitness = direct fitness + indirect fitness

Direct fitness:the component of personal fitness, due to the behaviour of the individual itself

Indirect fitness: made up of all the offspring of neighbours that can be attributed to its own behaviour

However, all non-descendant offspring are not valued equally, and are not as valuable as the own actors prodgeny. Introduces the concept of relatedness

Question 6

Inclusive fitness

Answer 6

The actor accrues more indirect fitness from helping genetically similar relative than by providing the same benefit for a less-related neighbour.

Relatedness provides an ‘exchange rate’ that allows non-descendant offspring to be translated into effective numbers of descendant offspring.

Question 7

Kin selection theory

Answer 7

A behaviour is favoured when it leads to a net increase in the inclusive fitness of the actor

Altruisti (cooperative) act spreads if:

benefit to recipient x relatedness > cost to altruist

Question 8

Coefficients of relatedness in microorganisms

Answer 8

Transfer genes horizontally, independent of reproduction events

Traits are carried on mobile genetic elements

Question 9

Game theory

Answer 9

Conceivd by von Neumann and Morgenstern

Mathematic framework: how cooperative entities can overcome the obvious fitness and payoff disadvantages and persist in the face of cheating and exploitation

Maynard Smith and Price related the economic concept of payoff function with evolutionary fitness

Question 10

Prisoners dilemma

Answer 10

Betray or cooperate