Chapter 13 - Cooperation and Conflict

Give example of how species can cooperate with each other to help

1) Females take care of the young while men are away

2) Worker and soldier ants serve their Queen ant

How is the Evolution of Social Interactions classified?

Based on how the fitness of the actor and recipient is affected

Describe each box of the Evolution of Social Interactions table

1) Mutually Beneficial —> both actor and recipient gain fitness

2) Selfish —> actor gains, recipient loses

3) Altruistic —> actor loses, recipient gains

4) Spiteful —> both actor and recipient lose fitness

How does cooperation and conflict play into the Evolution of Social Interactions

Cooperation will occur when an individual’s actions benefit another (even when it doesn’t help them) —> Mutually Beneficial, Altruistic

Conflict occurs when fitness interests differ

What is inclusive fitness and who made it?

William D. Hamilton made it

It is a combination of direct and indirect fitness

Define indirect fitness

Indirect fitness is passing genes by AIDING a relative’s production

Define direct fitness

Passing genes through ONE’S OWN offspring

Describe Cooperation Among Unrelated Individuals

Natural selection will favor cooperation when DIRECT FITNESS outweighs COSTS

• Flocks, schools, herds all reduce predation risk (direct fitness > cost)

  • Wolves hunt in packs to get prey they couldn’t get alone (direct fitness > cost)

What are the delayed benefits of cooperation in terms of Cooperation Among Unrelated Individuals

This is when a future opportunity opens for an organism

Ex) A beta manakin will assist an alpha in its courtship displays

• Beta itself won’t mate but it may inherit THAT display site later —> giving it a possible future opportunity

Define reciprocity

This is when individuals help each other with the expectation of returns (getting help)

What are the conditions of reciprocity

1) Repeated interactions

2) Ability to recognize and remember others
3) The benefits are GREATER THAN (>) that cost of helping
4) This occurs often in fish, birds, and mammals

Give an example of reciprocity

1) Vampire bats will regurgitate blood and share it with unrelated bats —> lowers starvation rate

2) Yellow baboons will pull ticks off of each other (groom) —> higher offspring survival

How do organisms make sure each other behave in cases of reciprocity?

Punishment and Sanctions

• Cooperation strengthens when selfish organisms/individuals are punished

What are the five levels of selection in the context of cooperation and conflict

1) Selfish DNA

2) Selfish Mitochondria

3) Selfish Symbiont

4) Group Selection

5) Species SelectionD

Define Selfish DNA 

Selfish DNA is when a DNA sequence increases its own transmission whether or not it is beneficial or harmful to that organism

• Natural selection will favor entities that leave more copies of itself 

What are the consequences of Selfish DNA

1) Can reduce host fitness by causing low fertility or harmful mutations

2) Drives genetic conflict within genome itself

3) Can accelerate evolution by increasing mutation rates or making new genetic variationW

What is an example of selfish DNA

1) Segregation Distortion/Cheating Meiosis

• Mutations changing the probabilities of traits being passed on (>50%)

2) Transposons (Jumping Genes)

• DNA sequences that copy and insert themselves anywhere in the genome

What is selfish mitochondria?

Selfish mitochondria is when mitochondrial DNA replicates itself to pass on more copies of itself

What is Selfish Symbionts?

Organisms living inside of a host that take care of themselves first even if it hurts the host

Symbionts relationships —> symbionts provide a service to host like essential nutrients or protection

What is group selection?

Natural selection acting on a whole group

• Traits are beneficial for groups to survive

Pathogen virulence: selection favors intermediate virulence balancing transmission and host survival

What is species selection 

When NS acts on an entire species

• traits increase speciation rate or decrease extinction rate 

• NS favors traits with higher fitness