Unit 3 Key Area 6

Question 1

What is meant by the term social hierarchy?

Answer 1

A social hierarchy is a rank order in a group of organisms consisting of a dominant member and subordinate members.

Question 2

How do social hierarchies reduce conflict within a group of organisms?

Answer 2

Dominant members of the social hierarchy carry out ritualistic (threat) displays. Whilst any subordinate individuals will carry out appeasement behavior. This reduces conflict within a social group of organims.

Question 3

What is the evolutionary advantage for dominant individuals of the social hierarchy?

Answer 3

Social hierarchies increase the chances of dominant organisms advantageous genes being passed onto offspring.

Question 4

What is the benefit of animals forming alliances within social hierarchies?

Answer 4

Forming alliances within social hierarchies increases social status within the group.

Question 5

What are the advantages of being a subordinate member of a social hierarchy?

Answer 5

Subordinate members of the social hierarchy still benefit because of cooperative hunting.

Question 6

What are the benefits of cooperative hunting?

Answer 6

• Cooperative hunting benefits both dominant and subordinate members of a social hierarchy as they gain more food than if they were foraging alone.
• Less energy is used per individual
• Cooperative hunting enables larger prey to be caught and increases the chances of success of a hunt.

Question 7

What is the benefit of social defence strategies?

Answer 7

Social defence strategies increase the chances of survival for members of a group as certain individuals can hunt for food while other individuals of the group keep watch for predators. Social defence mechanisms also allow groups of animals to form specialised formations when under attack. This increases the chances of survival of their young.

Question 8

Define altruistic behavior?

Answer 8

A behavior that harms the donor individual but benefits the recipient

Question 9

Define what is meant by reciprocal altruism?

Answer 9

When the roles of donor and recipient are later reversed from the first altruistic behavior. This type of behavior is common place in social animals.

Question 10

What is the evolutionary advantage for the donor organism in altruistic behavior?

Answer 10

The donor organism will benefit in terms of kin selection in terms of increased chances of survival of shared genes in the recipient’s offspring or future offspring.

Question 11

What are the different types of social insects?

Answer 11

• Ants
• Bees
• Wasps
• Termites

Question 12

How do social insects structure their society?

Answer 12

Only some organisms will contribute reproductively (queens and drones). Most members of a colony are sterile workers that cooperate with closely relatives to raise relatives.

Question 13

Give some examples of worker roles within social insects society?

Answer 13

• defending the hive
• collecting pollen
• carrying out waggle dances to indicate the direction of food

Question 14

How do worker insects benefit from the colony structure?

Answer 14

As raising relatives increases the chances of survival of shared genes

Question 15

Why do primates have such an extended period of parental care?

Answer 15

to allow offspring to learn the complex social behaviors. These complex social behaviors support the social hierarchy and reduce conflict through ritualistic display and appeasement behavior

Question 16

Give examples of complex social behaviors in primates?

Answer 16

• grooming
• facial expressions
• body posture
• sexual presentation