Evolutionary Psycholog
Exam
Wednesday 26/10 12:15 - 14:40 RAI
Resit exam
Monday 19/12 15:30 - 17:45 IN 0B60
y
,Lecture 1 - Chapter 1 &
The scientific movements leading to evolutionary psychology
Evolutionary psychology: understanding the human mind, human behaviour (effect and
cognition) from an evolutionary perspective. It means viewing humans as part of the
animal kingdom, subject to the same laws of evolution, natural selection
- Evolution: change over time
4 key questions:
- Why is the mind designed the way it is (what processes shaped the mind)
- How is the mind designed (what are the mechanisms)
- What is the mind designed to do (what are the functions)
- How does input from the current environment interact with the design of the mind to
produce observable behaviour
History of evolution:
Greek philosophers (600 BC)-> Artistoteles (300 BC)-> Christianity medieval (16th
century)-> Lamarck (18th century)-> Darwin (19th century)-> Mendel (19th century)->
DNA discovery
Lamarck (18th century)
1. Natural tendency for species to progress toward a higher form
2. The inheritance of acquired characteristics and the use and disuse of traits (e.g.,
muscles)
- Animals that struggle to survive cause their nerves to secrete a fluid which enlarges
organs involved in the struggle. These organs are passed down to succeeding
generations
• Giraffe: long necks to eat from higher leaves / long necks in mate competition
Cuvier - catastrophism - species are extinguished periodically by sudden catastrophes
(meteorites) and replaced by different species
Change in species suggested life is not static or fixed but forever changing: comparing
species (flippers on birds and seals), bones differ in different geological strata, comparing
embryological development of different specifies
Darwin - Theory of Natural Selection - survival of the fittest: best adapt
The existence of adaptations: why do organisms appear so well designed for their
environment/ Why do component parts of animals exist in that particular form
- Formation of new adaptations: struggle for existence: favourable variations are
preserved, unfavourable variations die out
2
,Species can change over time: Galápagos’ different finches had a common ancestors but
had become different from each other because of the local ecological conditions on each
island
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 form
We share the same ancestors with chimpanzees
Natural selection: changes over time due to the differential reproductive success of
inherited variants
- Variation: organisms vary in all sorts of ways
- Inheritance: some variations are inherited
- Selection: organisms with heritable variants leave more offspring because those
attributes helped survival or reproduction
• A particular finch has a better adapted beak to gather food than others (heritable
variant), increases survival chance and pass their inherited quality over via
reproduction
• The giraffe neck: there is individual variation in traits, some of these traits variants
allow the bearer to compete for better resources. If the traits are inheritable they are
passed on to the next generation. Result: individual species becomes better adapted
to their environment
Intelligence is natural selection
Mutation gives an advantage and the one with the mutation will have more offspring.
Epigenetic
Natural selection & genetic drift cause evolutionary change
Natural selection acts on variants that already exists, it is gradual
Punctuated equilibrium: long periods of no change, followed by relatively sudden change
Natural selection: successful survival causes adaptations
- Causal process by which change takes place over time
- Theory to account for origin of new species
- Unites all living forms into one grand tree of descent
Sexual selection: successful mating causes adaptations
- evolution of characteristics due to success in mating
Sexual selection: you are more attractive to be picked by a partner. Psychical attraction
, - Intersexual competition: individuals of the opposite sex who posses desired qualities
are chosen as mates. Traits that are passed on because they are good at attracting
opposite sex mates (peacock feathers)
- Evolutionary change occurs: qualities that are desired in mates increase in frequency
with the passing of generation (female choice)
- Intrasexual competition: competition between members of one sex. Traits that are
passed on because they are good at winning same sex competitions for mates (stag
fight: winner gets access to mating with the other sex / gossiping)
- Evolutionary change occurs: qualities that lead to success are passed on, and the
loser fails to reproduce
Runaway effects in sexual selection: some men are strong, women prefer strong men so
they give a strong son (reproductive success)/daughter who likes strong men, who gives a
strong son. Result = men are getting stronger and stronger
Genetic drift: evolutionary change because of random changes in the genetic makeup of
a population through
- Mutation: random hereditary change in the DNA
- Founder effects: small portion of a population establishes a new colony and the
founders of the new colony are not genetically representative of the original population
- Genetic bottlenecks: population shrinks due to random catastrophes and the survivors
carry only a subset of the genes of the original population
Objections: species are unchanging (God’s plan), not imaginable how the early stages of
the evolution of an adaption are useful (a partial wing), controversy about a common
ancestor, qualities of the parents are passed on intact through ‘genes’ (not acquired
through experience)
Mendel - genes - inherited intact by an offspring
genotype: entire collection of genes within an individual, not passed on intact but inherit
half of genes from mother’s and half of father’s genotype
Ethology (Lorenz and Tinbergen): study of proximate mechanisms and adaptive value of
animal behaviour (imprinting)
Innate properties of animals: fixed action patterns are stereotypic behavioural sequences
an animal follows after being triggers by a well-defined stimulus
Hamilton - inclusive fitness theory - the sum of an individual’s own reproductive success
(classical fitness) PLUS the effects the individual’s actions have on the reproductive success
of his/ her genetic relatives
- Ensure well-being of the body for survival
