Lecture 4 Flashcards
Evolution
Descent with Modification
Natural Selection
- Replication
- Competition for Resources
- Copying errors (Mutation)
- Differential Replication
- Appearance of Design
Vatican Theory
Descartes
Body evolves but the mind does not evolve
Evidence of Evolution in Brain
- Fossil Record*: Later species have larger brain, and showed evidence of more complex behavior
- Development*: Grasping Reflex
- Biogeography*: Darwin predicts ancestral fossils in Africa because chimps live there
- Homologies*: Homologies in brain between species are seen: vision, memory, emotions, mood
- Vestigial Expressions*- Goosebumps, rage expression
Misconception About Complexity
Natural Selection Moves towards Greater complexity, Humans are most highly evolved
Natural selection does not push species in a ladder, in a niche within a tree
Selects for traits that increase reproductive success, not intelligence
Misconception about Environment
Assumed humans are completely adapted to the environment
Can only adapt to the past environment, hunter gatherer life many years ago
Ultimate Causation
What is evolution trying to accomplish?
Proximate Causation
What does the brain cause behavior? what does it desire to accomplish?
Spandrel
By-product traits of natural selection
Reverse Engineering
Process to find out the evolutionary causes of a trait
- Identify a goal of the adaptation
- Characterize the environment
- Decide the design of the trait that would allow this goal
- Study the organism to see if it has the trait
Case Study: Pregnancy sickness
- Many foods in the wild are teratogenic
- Hypersensitive smell
- Arises when embryo is developing and ceases when development ceases
- Most foods avoided contain the most toxins
- Negatively correlates with birth defects
- Cross Cultural
Case Study: Homosexual men
Paradoxical to evolution because they avoid heterosexual sex, and therefore the spread of their genes
Hypothesized: Take more care of siblings children FALSE
Real cause still unknown
