Lecture 2

Question 1

What are the three necessary and sufficient conditions for natural selection to occur?

Answer 1

1. Variability in population
2. Competition for resources needed for survival & reproduction
3. Resemblance of offspring to parents

Question 2

What is variability in natural selection?

Answer 2

Different individuals have different traits, both physical and behavioral.

Question 3

What are sources of variation between individuals?

Answer 3

• Acquired: Nutrition, exercise, learning
• Genetic: Inherited from parents, genetic mutations

Question 4

What is an example of natural selection observed in finches?

Answer 4

During the 1977 drought, 83% of Geospiza fortis (Medium Ground Finch) died. The next generation had beaks 4% larger to crack tougher seeds.

Question 5

How does competition drive natural selection?

Answer 5

Individuals with more adaptive traits have greater fitness—better at getting food, avoiding predators, and attracting mates, leading to healthier offspring.

Question 6

What are the three levels at which competition occurs in natural selection?

Answer 6

1. Group level: Between groups of individuals (e.g., species competing for ecological niches)
2. Individual level: Between individuals within a species (e.g., stronger tiger shark embryos survive)
3. Genetic level: Genes competing with each other (e.g., genomic imprinting)

Question 7

What is the controversial concept of ‘group selection’?

Answer 7

The idea that traits beneficial for the group (e.g., altruism, food-sharing) may be selected for, despite potential costs to individuals.

Question 8

How does genomic imprinting illustrate genetic competition?

Answer 8

Some genes ‘know’ which parent they came from, influencing traits like fetal growth to either conserve (mother’s genes) or maximize (father’s genes) resource use.

Question 9

What are the three guiding assumptions of evolutionary psychology?

Answer 9

1. The brain evolved to generate behavior suited to ancestral environments.
2. Different neural circuits evolved to solve different challenges.
3. Most human-specific cognition evolved in the Pleistocene epoch (2.5 million–12,000 years ago).

Question 10

What is the Environment of Evolutionary Adaptation (EEA)?

Answer 10

The ancestral environment where human traits evolved, shaping modern cognition and behavior.

Question 11

What challenges shaped human evolution?

Answer 11

• Obtaining food
• Avoiding predators
• Finding mates
• Raising offspring
• Navigating social interactions (status, alliances, conflicts)

Question 12

What was Charles Darwin’s view on the evolution of psychology?

Answer 12

He proposed that mental abilities evolved gradually, just like physical traits (On the Origin of Species, 1859).

Question 13

How did William James contribute to evolutionary psychology?

Answer 13

He argued that humans have many instincts, contrary to the belief that instincts are more common in animals.

Question 14

What was B.F. Skinner’s radical behaviorism?

Answer 14

The belief that all behavior is shaped by environmental reinforcement, rejecting the idea of innate human nature.

Question 15

How did Noam Chomsky challenge behaviorism?

Answer 15

He argued that behaviorism couldn’t explain language acquisition and other complex cognitive functions, leading to the Cognitive Revolution.

Question 16

What are examples of ‘privileged stimulus-response pairings’ that challenge behaviorism?

Answer 16

1. Pigeons learn to peck for food but not to flap wings for food.
2. The Garcia Effect: Humans associate nausea with food, not lights or sounds.
3. Prepared phobias: Humans fear snakes/spiders more easily than knives, even without prior experience.