750 likes | 976 Views
How is language originated?. Gestural language and vocal language depend on similar neural systems. Nonhuman primates can use gestures or symbols for primitive communication. Gestural theory: Human language developed from gestures that were used for communication. .
E N D
Gestural language and vocal language depend on similar neural systems. Nonhuman primates can use gestures or symbols for primitive communication. Gestural theory: Human language developed from gestures that were used for communication.
Gestural learning and speech learning : around the same cortex region -- Gestural language in chimps
2. Infant babbling Moving their limbs while making the babbling sounds.
Gestural language and vocal language depend on similar neural systems. Nonhuman primates can use gestures or symbols for primitive communication. Gestural theory: Human language developed from gestures that were used for communication.
Gestural language in chimpanzees Associate words objects Associate words signs
domestication relaxed selection pressure for stereotypic songs in the songbirds… 2. Culture-domestication theory: our cultural domestication have relaxed selection on many of our primate behavioral traits, allowing old pathways to degenerate and reconfigure.
In Nature In the lab Black-capped chickadee:
Domesticated foxes have high behavioral variability Many traits have changed in the domesticated farm foxes Floppy ears, curled tails Patches of white fur Lost musky fox smell Barking, wagging tails, licking humans Reduce fear response (corticosteroid)
How is language originated? Evolution of vocal tract?Evolve from gesture language?Evolve from cultural domestication
Last chapter! Evolution of human behavior
Is there a role for evolutionary theory in helping us to understand ourselves?
Human behavior is shaped by natural selection? Natural selection: Our behavioral attributes should help us pass on our genes to the next generation.
How about Culture? Cultural tradition influences our behavior
Evolution theory provides us a testable hypothesis for us to better understand ourselves
Blood-donationEvolutionary adaptive?Cultural dependence?
Food sharing in blood-sucking vampire bats Tit for tat strategy Female bats regurgitate blood meals to others that failed to obtain food
Altruism in Pied kingfisher O= offspring; s = p of survival to next year; m= p of finding a mate in the second year
Hamilton’s rule: altruism can evolve if: *Cx rc<*bxrb If the relatedness of the altruist to the relatives it helps (rb) is particularly high, then indirect fitness would be increased.
Animals: altruistic behavior Indirect benefit from inclusive fitness Direct benefit: Chance to acquire resource/ reproductive success
Blood-donationEvolutionary adaptive?Cultural dependence?
Evolutionary hypothesis of blood donation: Blood donor is repaid by the donor’s everyday’s companions.
How do you test this hypothesis? Prediction: donors should let their friends know… √
How do you test this hypothesis? Prediction: people will be reluctant to broadcast their refusal to donate… √
How do you test this hypothesis? Prediction: when people have a choice of other people to help, they prefer to help…… √
Rich diversity of human traditions: How can human culture be due to natural selection?
White-fronted bee-eaters Complex social decision
Female helper White-fronted bee-eaters
Complex social decision Females base their reproductive decisions on their behavioral flexibility and sophisticated evaluations of their social environment.
Humans base their reproductive decisions on their behavioral flexibility and sophisticated evaluations of their social/ cultural environment. Complex social decision
Arbitrary culture theory Our culture reflects arbitrary process by which traditions originate and persist over time. --Nothing to do with fitness
Your oral presentation Eye contact Few words per slide Focus: one topic Timing Organize Memorize Practice
Rich diversity of human traditions: Is human culture partially selected by natural selection?
Final exam question: Can Blood-donationbe explained byevolutionary theory?
Final exam question: Adoption Is adoption simply a culture phenomenon, or it has its evolutionary roots?
Evolutionary hypotheses for adoption is supported by Inclusive fitness: 2. Direct benefit:
Most adopters cared for children who were cousin or closer (r=0.125)
Alternatively, adoption is supported by mal-adaptive hypothesis Adaptive proximate mechanisms for love and care of children: mal-adaptive
Mal-adaptive hypothesis Predictions: Couples lost the only child,or fail to produce children,prone to adopt stranger
Mal-adaptive hypothesis animal examples?
Mal-adaptive hypothesis animal examples?
Evolutionary theory for adoption is supported by Inclusive fitness: 2. Direct benefit: 3. Mal-adaptive proximate mechanism
Final exam question: Mate choice Mate choice in humans: has its evolutionary roots?
Evolutionary models of mate choice in animals • 1. Good gene hypothesis • 2. Direct benefit hypothesis • 3. Runaway hypothesis • 4. Sensory exploitation hypothesis