Chapter 8

Question 1

What is life history theory?

-Understand life history trade-offs and energy allocation

Answer 1

-Life history theory
-Trades offs ( evolved strategies, not conscious decisions)
Quantity and quality of offspring
Current and future reproduction
Females involves access to resources
Males involve competitions to gain access to females.
-Energy allocation- growth, maintenance, reproduction
- Selection has favored different life history strategies depending on what maximizes reproductive success.

Question 2

Why do primates live such long lives and have such large brains?

Answer 2

-Evolution of the large primate brain:
1) Social intelligence hypothesis -compete for food and access to mates, navigate the complex social world of primates.
2) Behavioral flexibility hypothesis:
Ecological challenges
Mental mapping of fruit or other resources
Extractive foraging hypothesis -crack open nuts, dig for termites
Helps explain how primates going to cope with new challenges:
- Cope with both ecological and social challenges
- Learn new solutions to problems from others

Primates have long life histories
Slow maturation, large brains, long gestation, small litter, long lifespan
Variations in life history strategies within primates
Monkeys have lower life history than strepirrhines
Apes have lower histories than monkeys

Large brains in the apes has been driven by ecological challenges and the benefits of behavioral flexibility related mostly to food acquisition.

Question 3

What were the selection pressures that favored intelligence and brain enlargement in primates?
-Understand the Social Intelligence Hypothesis and Behavioral Flexibility Hypotheses

Answer 3

• -Evolution of the large primate brain:
  1) Social intelligence hypothesis -compete for food and access to mates, navigate the complex social world of primates.

2) Behavioral flexibility hypothesis:
Ecological challenges
Mental mapping of fruit or other resources
Extractive foraging hypothesis -crack open nuts, dig for termites
Helps explain how primates going to cope with new challenges:
- Cope with both ecological and social challenges
- Learn new solutions to problems from others

Primates have long life histories
Slow maturation, large brains, long gestation, small litter, long lifespan
Variations in life history strategies within primates
Monkeys have lower life history than strepirrhines
Apes have lower histories than monkeys

Large brains in the apes has been driven by ecological challenges and the benefits of behavioral flexibility related mostly to food acquisition.

Question 4

What do primates actually know and how can we figure that out?
-Be familiar with the studies that have been used to measure primate intelligence and social awareness

Answer 4

-Primate intelligence :Coalitions
Coalition formation
Victim, ally, and aggressor
- Understanding who these individuals are is critical to make the right choice
-Ally- helps the victim, negatively affects aggressor

Rules for alliance in Capuchins
Support females
Support dominants
Support close associates

Question 5

Do monkeys and apes have a theory of mind?
-Understand what theory of mind is, how we know whether primates have it, and why it’s important for understanding intelligence

Answer 5

-Theory of mind
Monkeys and apes can predict the action of others
Associative learning
Recognizing the relationship between one event and another
Theory of mind is ability to empathize, pretend, teach, see things from another point of view
Situations that require knowledge of another’s mind
Humans have theory of mind
Do other primates?
Deception
Humans aren’t the only great apes that can read minds

Human ability to navigate social situations and our theory of mind is significantly more developed than that of our closest relatives

Question 6

Extracted foods

Answer 6

-food that is embedded in a matrix, encased in a hard shell, or other wise difficult to extract. These foods require complicated, carefully coordinated techniques to process.

Question 7

Neocortex ratio

Answer 7

-the size of the neocortex in relation to the rest of the brain.

Question 8

Third-party relationships

Answer 8

-relationships among other individuals. For example monkey and apes are believed to understand something about the nature of kinship relationships among other group members.

When one individual understands what is going on between the two others

Question 9

Redirected aggression

Answer 9

-a behavior in which the recipient of aggression threatens or attacks a previously uninvolved party. For instance, if A attacks B and B then attacks C, B’s attacks are an example of redirected aggression.

Question 10

≥

Answer 10

Selection has favored an allocation of energy towards an increase in brain size.

Question 11

Big brains long lives

Answer 11

Primates:
Large brains
Long childhood 
Learned behaviors 
Behavioral flexibility 
Long lives

Question 12

Across all mammals, brain size is correlated with

Answer 12

Life span.

Question 13

Brain tissue is

Answer 13

Energetically expensive to grow.

Question 14

Brain weighs

Answer 14

2% of our body, but consumes 20% of our energy.

Question 15

Understand traits of slow v. fast life history

Answer 15

Fast life history :
Reproduce early
Small body 
Small brain 
Short gestation 
Large litters
High morality rates 
Short life span. 

Slow life history:
Reproduce late
Large body
Large brain 
Long gestation 
Small litters
Low morality rate
Long life span. 

Selection is constantly operating on these Life history features to maximize reproductive fitness in whatever environment a population finds itself.

Question 16

Neocortex

Answer 16

Folded, outer layer of the cerebrum
Part of the brain most associated with problem-solving and behavioral flexibility
Most relevant to the discussion of primate intelligence

Question 17

Brain structure

Answer 17

Brain structure is divided into three parts
1) Hindbrain 
Cerebellum 
Brain stem
2) Mid brain 
Contains the optic lobe
3) Fore brain or cerebrum 
4 lobes 
Neocortex- outer layer of cerebrum 
Used to examine human intelligence

Question 18

Senescence

Answer 18

Means aging

Question 19

Why grow old and die.

Answer 19

Energy allocation towards growth and fertility at expense of longevity
Aging is thus partly a consequence of selection favoring genes that increase one’s fitness early in life at the expense of their fitness later in life.
Pleiotropic effects of genes that favor fertility
Example testosterone Which helps reproductive success in young males, high levels of testosterone ultimately lowers lifespan in male mammals.

Question 20

What do monkeys know about one another?

Answer 20

Regardless of the selective forces that led to the evolution of larger brains we know:
1) Primates are social
- Understanding of one’s place in the social hierarchy is critical to survival
— who’s dominant and who is submissive
— Critical to negotiate the delicate social interactions that occur
—When to join a coalition and went to avoid confrontation
-How do researchers know what monkeys know?
—Countless hours observing primates in the wild
—Learned in captive laboratory experiments
2) Primates are smart.

Question 21

Kinship

Answer 21

Monkeys know who is related to whom in a group

Question 22

Neocortex ratio in primates

Answer 22

Data from primates appear to support all of the hypothesis proposed to explain the evolution of intelligence in primates.
Neocortex ratio
Correlated with group size in primates
- thus the number of social interactions one needs to keep track of.
- Support for social intelligence hypothesis
Higher in fruit eating primates with larger home range
-Support for ecological based behavioral flexibility hypothesis
Higher in primates that have been observed coming up with novel solutions to problems, whether they be social learning or tool use.
Larger parts of the brain devoted to higher thinking.

Question 23

Re-directed aggression

Answer 23

When vervet monkeys are attacked, they take out their frustration on the maternal kin of the monkey that originally attacked them and started the feud.

Question 24

Case study at Kenya’s Amboseli national park

Answer 24

Researchers artificially played through loud speakers the alarm call of a juvenile vervet monkey.
Then observed other members of the group
Group members looked at the direction of the juvenile

Question 25

Human social cognition

Answer 25

Primates are intelligent
How are humans different?
2 year old children versus adult apes
-Physical task equal (retrieving food using a tool)
- Social task (solving a problem after watching someone demonstrate a solution)
Humans outperform apes
Our ability to navigate social situations and our theory of mind is significantly more developed than that of our closest ancestors.

Question 26

Why study primates?

Answer 26

We are primates
We are similar to other primates in many ways -anatomically and behaviorally
We are different from other primates in many ways
When did these changes evolve.
Why did these changes happen in our line age