Lecture 1 What is evolution?
Short overview
● Evolutionary psychology is the study of human behavior, affect and cognition from an
evolutionary perspective
● Using evolutionary theory to understand why the human mind works this way and
how it has been designed
● In effect, it means viewing humans as part of the animal kingdom, subject to the
same laws of evolution, natural selection etc
○ This might seem contentious (but there is really no alternative)
History of evolution
● Greek philosophers 600-400 BC
● Aristoteles 300 BC
● Medieval Christianity 16th century
● Lamarck 18th century
● Darwin 19th century
● Mendel 19th century
● DNA discovery
And Modern Synthesis in Biology (20 century): 1. function (evolution) and 2. mechanism
(gene)
Evolution pre-Darwin
● Jean-Baptiste Lamarck (1744-1829)
○ The inheritance of acquired characteristics
○ Use and disuse of traits (ex. muscles)
● Example giraffe: the one with the longest neck, has more
babies and the neck grows more
Charles Darwin (1809-1882)
● The voyage of the Beagle (1831-1836)
● Book “on the origin of species” (1859)
Natural selection and survival of the Fittest
Quote Darwin:
“ As many more individuals of each species are born than can possibly survive; and as,
consequently, there is a frequently recurring struggle for existence, it follows that any
being, if it vary however slightly in any manner profitable to itself, under the complex and
sometimes varying conditions of life, will have a better chance of surviving, and thus be
naturally selected. From the strong principle of inheritance, any selected variety will tend
to propagate its new and modified from ”
Tree of Life
→ DNA-studies reveal that humans
share a common ancestor with a
Bacteria, some 4 billion years ago
1
,The Primate Tree
Charles Darwin (1809-1882): grandfather of evolutionary psychology
● “In the distant future I see open fields for far more important researches. Psychology
will be based on a new foundation”
What is evolution (via natural selection)?
● QUESTION
Three components of natural selection:
1. Variation
a. Variations between genes etc
b. Eye color, hair color etc
2. Inheritance
a. from parents, grandparents
3. Selection
a. A la expeditie robinson
2
,The giraffe neck: how does natural selection work
1. There is individual variation in traits
2. Some traits variants allow their bearers to better compete for resources
3. If these traits are inheritable then they are passed on from generation to generation
4. The result: individuals of a species become better adapted to their environments
A mechanism for evolution via natural selection: the gene
Gregor Mendel (1822-1884)
- if you cross a red gene the offspring with A white one = red
- Red x white = also red
- White x White = white
➔ Dominant allele
➔ The blue eye gene will eventually go extinct
The modern synthesis in biology and DNA discovery (1953)
1. Mixing parental genes (mendelian genetics)
2. Recombination
3. Mutation
Sexual selection → EXAM!
2 forms of sexual selection
1. Inter sexual competition = women and men
a. traits that are passed on because they are good at attracting opposite sex
mates
i. for example: pretty feathers of birds
ii. Peacock’s tail is used for sexual selection → makes you more
attractive to the other seks
2. Intra sexual competition = men vs men
a. traits that are passed on because they are good at winning same sex
competitions for mates
i. for example: stag fight for men, gossiping for women
Runway effects in sexual selection
3
, Humans are the product of evolution
● Muscles, veins, organs, bones
● Incredibly complex
● Not perfect, but functionally adapted to certain environment
● the environment …
… The Savannah Hypothesis: selection has favored preferences, motivation and
decision rules to explore and settle in environment abundant with the resources
needs to sustain
1) selection
2) Information gathering
3) exploitation
We prefer landscapes with open field, water and trees
➔ walking upright you can look further, see each other, pray and dangers faster.
➔ You walk faster upright etc
The most complex organ of all: the brain
● Triune Brain (Maclean, 1960)
● Illustrative:
○ Reptilian brain, brain stem (avoid and approach)
○ Paleo-mammalian complex, emotions (limbic system)
○ Neo-mammalian complex, planning (neo cortex)
Increase in brain size
● Was a lot smaller, now 1.5 kg of brains, consumes 20% of our caloric intake
What factors drove the increase in the hominid brain size?
● Ecological factor (e.g. climate)
● Technology
● Social factors
● Cultural factors
History of evolutionary psychology
● Sigmund Freud: sex is important
● William james: we have lots of instincts
● Skinner’s behaviorism: anything can be learned as long as it is rewarded (harlow and
garcia)
● Evolutionary psychology by cosmides and ttooby: the brain is a swiss army knife, the
mind can adapt to its environment. Learning and culture require evolved
mechanisms.
● Dawkins: selfish gene → its not so much by you, but the genes must be reproduced
● Sociobiology by Wilson: Sociobiology will “ cannabalize psychology” he argued that
evolution would produce a new perspective for social psychologist. Many cherished
human pneomene, such as culture, religon. WOuld ultimately be explained by the
new synthesis
4
Short overview
● Evolutionary psychology is the study of human behavior, affect and cognition from an
evolutionary perspective
● Using evolutionary theory to understand why the human mind works this way and
how it has been designed
● In effect, it means viewing humans as part of the animal kingdom, subject to the
same laws of evolution, natural selection etc
○ This might seem contentious (but there is really no alternative)
History of evolution
● Greek philosophers 600-400 BC
● Aristoteles 300 BC
● Medieval Christianity 16th century
● Lamarck 18th century
● Darwin 19th century
● Mendel 19th century
● DNA discovery
And Modern Synthesis in Biology (20 century): 1. function (evolution) and 2. mechanism
(gene)
Evolution pre-Darwin
● Jean-Baptiste Lamarck (1744-1829)
○ The inheritance of acquired characteristics
○ Use and disuse of traits (ex. muscles)
● Example giraffe: the one with the longest neck, has more
babies and the neck grows more
Charles Darwin (1809-1882)
● The voyage of the Beagle (1831-1836)
● Book “on the origin of species” (1859)
Natural selection and survival of the Fittest
Quote Darwin:
“ As many more individuals of each species are born than can possibly survive; and as,
consequently, there is a frequently recurring struggle for existence, it follows that any
being, if it vary however slightly in any manner profitable to itself, under the complex and
sometimes varying conditions of life, will have a better chance of surviving, and thus be
naturally selected. From the strong principle of inheritance, any selected variety will tend
to propagate its new and modified from ”
Tree of Life
→ DNA-studies reveal that humans
share a common ancestor with a
Bacteria, some 4 billion years ago
1
,The Primate Tree
Charles Darwin (1809-1882): grandfather of evolutionary psychology
● “In the distant future I see open fields for far more important researches. Psychology
will be based on a new foundation”
What is evolution (via natural selection)?
● QUESTION
Three components of natural selection:
1. Variation
a. Variations between genes etc
b. Eye color, hair color etc
2. Inheritance
a. from parents, grandparents
3. Selection
a. A la expeditie robinson
2
,The giraffe neck: how does natural selection work
1. There is individual variation in traits
2. Some traits variants allow their bearers to better compete for resources
3. If these traits are inheritable then they are passed on from generation to generation
4. The result: individuals of a species become better adapted to their environments
A mechanism for evolution via natural selection: the gene
Gregor Mendel (1822-1884)
- if you cross a red gene the offspring with A white one = red
- Red x white = also red
- White x White = white
➔ Dominant allele
➔ The blue eye gene will eventually go extinct
The modern synthesis in biology and DNA discovery (1953)
1. Mixing parental genes (mendelian genetics)
2. Recombination
3. Mutation
Sexual selection → EXAM!
2 forms of sexual selection
1. Inter sexual competition = women and men
a. traits that are passed on because they are good at attracting opposite sex
mates
i. for example: pretty feathers of birds
ii. Peacock’s tail is used for sexual selection → makes you more
attractive to the other seks
2. Intra sexual competition = men vs men
a. traits that are passed on because they are good at winning same sex
competitions for mates
i. for example: stag fight for men, gossiping for women
Runway effects in sexual selection
3
, Humans are the product of evolution
● Muscles, veins, organs, bones
● Incredibly complex
● Not perfect, but functionally adapted to certain environment
● the environment …
… The Savannah Hypothesis: selection has favored preferences, motivation and
decision rules to explore and settle in environment abundant with the resources
needs to sustain
1) selection
2) Information gathering
3) exploitation
We prefer landscapes with open field, water and trees
➔ walking upright you can look further, see each other, pray and dangers faster.
➔ You walk faster upright etc
The most complex organ of all: the brain
● Triune Brain (Maclean, 1960)
● Illustrative:
○ Reptilian brain, brain stem (avoid and approach)
○ Paleo-mammalian complex, emotions (limbic system)
○ Neo-mammalian complex, planning (neo cortex)
Increase in brain size
● Was a lot smaller, now 1.5 kg of brains, consumes 20% of our caloric intake
What factors drove the increase in the hominid brain size?
● Ecological factor (e.g. climate)
● Technology
● Social factors
● Cultural factors
History of evolutionary psychology
● Sigmund Freud: sex is important
● William james: we have lots of instincts
● Skinner’s behaviorism: anything can be learned as long as it is rewarded (harlow and
garcia)
● Evolutionary psychology by cosmides and ttooby: the brain is a swiss army knife, the
mind can adapt to its environment. Learning and culture require evolved
mechanisms.
● Dawkins: selfish gene → its not so much by you, but the genes must be reproduced
● Sociobiology by Wilson: Sociobiology will “ cannabalize psychology” he argued that
evolution would produce a new perspective for social psychologist. Many cherished
human pneomene, such as culture, religon. WOuld ultimately be explained by the
new synthesis
4
