PSYC 385 Lecture Notes - Lecture 5: Sensation Seeking, Dopamine Receptor, Ariaal People
6 Jun 2018
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PSYC 385 – Class 5
May 23, 2018
Class 5: Key Concepts
▪ Anatomically modern vs. archaic humans
o Part of the Great Ape lineage
o Oldest AMC fossils are similar to our fossils
o Bipedalism
o Meat eating
▪ Gracile australopithecines adapted to softer foods (meat, plants) than robust (nuts)
o Tool use
o Brain size
▪ Neanderthals had bigger brains
▪ Big brains imply longer life spans, affects life history
▪ Big brains also need meat for fuel
▪ Babies are born helpless due to the slow development of the brain
o The “learning niche” allows AMC to adapt to environments
▪ Complex tools
▪ Sophisticated language, spatial and temporal references
▪ Neanderthals seem to lack a social brain
▪
▪ How do we define/design an AMH?
o Case-by-case analysis
o Thinking about the ancestral cases and mismatch arguments
o Implications for evolutionary theories of human behaviour from our brief look at the descent of anatomically
modern humans
▪ Out of Africa theory
o Human migration out of Africa 200k years ago
o Genetic and fossil evidence supports this theory
▪ Molecular clock estimation
o Genetic drifts can lead to overrepresentation or underrepresentation of genes
o Estimating the last common ancestor is possible due to the molecular clock concept
o “Neutral theory:” most of the DNA change is “selectively neutral” (most of genetic change was cause by genetic
drift)
o Molecular clocks use SNPs (Fielder & Huber, 2016) (in Adenine, Cytosine, Guanine, Thymine ☺)
▪ Genetic support for Out of Africa
o Relatively small group of individuals that leaves Africa and slowly colonizes other parts of the world
o Pääbo et al. have found inbreeding of early modern humans and archaics
o Anyone of non-African descent currently carries ~2% Neanderthal DNA
o Anyone of Melanesian descent currently carries an additional ~5% Denisovan DNA
▪ Readings: Gayon (2016) and Fielder and Huber (2016)
▪ Classical vs. molecular genetics
o Gayon (2016) reviews problems for molecular concept of gene: finds no general definition!
▪ Definition changes over time
▪ Abstraction for a very complicated process
o Classical genetics:
▪ Roots in Mendel: looked at observable characteristics to infer how genes worked
▪ Gayon (2016): what we think of as a gene is a problematic thing
o Molecular genetics:
▪ Gayon (2016): a lot of different molecular processes that regulate gene expressions
o Newer developments of Gayon (2016):
▪ Challenges the traditional one gene-one protein dogma
▪ 98.5% of genome not translated to proteins
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Information flows in one direction one way flow of the information from the dna to the rna, and then to the proteins: useful way of explaining gene function (how genotypes influence phenotypes), generally useful but not always useful. In a statistical sense, are computed by comparing the amount of variation in what are classified as genetic versus environmental effects. A heritability estimate is also specific to the population and environment based on. To put this differently it is not generalizable: characteristics of a population, directly measuring genetic variants, heritability estimate for height in large sample of european well-nourished men is about . 80, problem of missing heritability. 2: lack of correspondence though between heritability estimates and genetic variants associated with phenotypes is. 3 common: most phenotypes are affected by multiple genes, single genes having multiple phenotypic effects, lack the right amount of genetic information.
