PSYC 391 Chapter 3: PSYC 391 CH3 Gene-Culture Co-Evolution
4 Oct 2018
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PSYC 391 CH3 Gene-Culture Co-Evolution
How did we get here?
- Big brains (encephalization)
- Slow life-story (altrical)
- Shortened gut (w/ fire)
- Slender build (gracile)
The human socio-cognitive niche
- The human socio-cognitive niche
- A evolving suite of social, cognitive and cultural adaptations
- Cooperation: division of labor, sharing of large game, intergroup
competition
- Egalitarianism: need-based helping, leveling, low reproductive skew
- all people are equal and deserve equal rights and opportunities.
- Language: coordination, teaching, cognitive tools, rules
- Theory of mind: perspective taking, intention understanding, imitation,
coordination
- Cumulative culture: “ratchet effect”, complex knowledge, technology,
institutions
Humans evolved in Africa, and only recently (~100KYA) migrated out across the globe
■ Three major consequences:
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1. Shared human meta-culture
- All humans are genetically quite similar
- Sophisticated communication & cultural learning capacities
- Universal developmental norms of reaction to environment
- Metaculture: All the universal concepts that are present in all cultures.
2. Cultural adaptation to diverse environments
- Cumulative cultural evolution in all the world’s ecosystems
- Diverse ecologies, economies, diets, social organizations, tools, etc
3. Recent gene-culture co-evolution within populations
- Within some domains with high impact on genetic fitness
- The reproductive success of a genotype, usually measured as the
number of offspring produced by an individual that survive to
reproductive age relative to the average for the population.
- Eg, climate, diet, pathogens
How do we explain observed variation?
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Genetic variation doesn’t explain most human phenotypic variation
- Humans are less genetically variable than chimpanzees, & more human variation is
within populations than between
■ Serial founder effect reduces genetic
variation further away from Africa
- the founder effect is the loss of
genetic variation that occurs when a
new population is established by a
very small number of individuals from
a larger population.
Document Summary
A evolving suite of social, cognitive and cultural adaptations. Cooperation: division of labor, sharing of large game, intergroup competition. Egalitarianism: need-based helping, leveling, low reproductive skew. All people are equal and deserve equal rights and opportunities. Theory of mind: perspective taking, intention understanding, imitation, coordination. Cumulative culture: ratchet effect , complex knowledge, technology, institutions. Humans evolved in africa, and only recently (~100kya) migrated out across the globe. Universal developmental norms of reaction to environment. Metaculture: all the universal concepts that are present in all cultures: cultural adaptation to diverse environments. Cumulative cultural evolution in all the world"s ecosystems. Diverse ecologies, economies, diets, social organizations, tools, etc: recent gene-culture co-evolution within populations. Within some domains with high impact on genetic fitness. The reproductive success of a genotype, usually measured as the number of offspring produced by an individual that survive to reproductive age relative to the average for the population. Genetic variation doesn"t explain most human phenotypic variation.
