Chapter 8 Flashcards
What is life history theory?
-Understand life history trade-offs and energy allocation
-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.
Why do primates live such long lives and have such large brains?
-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.
What were the selection pressures that favored intelligence and brain enlargement in primates?
-Understand the Social Intelligence Hypothesis and Behavioral Flexibility Hypotheses
- -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.
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
-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
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
-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
Extracted foods
-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.
Neocortex ratio
-the size of the neocortex in relation to the rest of the brain.
Third-party relationships
-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
Redirected aggression
-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.
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Selection has favored an allocation of energy towards an increase in brain size.
Big brains long lives
Primates: Large brains Long childhood Learned behaviors Behavioral flexibility Long lives
Across all mammals, brain size is correlated with
Life span.
Brain tissue is
Energetically expensive to grow.
Brain weighs
2% of our body, but consumes 20% of our energy.
Understand traits of slow v. fast life history
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.
Neocortex
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
Brain structure
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
Senescence
Means aging
Why grow old and die.
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.
What do monkeys know about one another?
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.
Kinship
Monkeys know who is related to whom in a group
Neocortex ratio in primates
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.
Re-directed aggression
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.
Case study at Kenya’s Amboseli national park
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
