PS263 – Chapter 2: Evolution, Genetics & Experience
In the beginning human processes fell into two categories: physiological or
psychological – after the Dark Ages, Descartes argued the universe was
composed of: 1) physical matter – according to laws of nature & a suitable
object of scientific investigation 2) the human mind which lacks physical.
Cartesian Dualism: the Roman Church sanctioned his theory, that the human
brain and the mind are separate entities.
Whether humans inherit their behavioural capacities or acquire them
through learning is referred to as nature-nurture issue.
Watson’s theory of behaviorism: ethology is the study of animal behaviour in
the wild and instinctive behaviours that occur in all like members of a
species even when there seems to have been no opportunity for learned.
Evidence against physiological or psychological thinking (assumption that
some aspects of human psychological functioning are so complex they could
not be a product of the physical brain)
Asomatognosia: a deficiency in the awareness of parts of ones own body –
typically involving the left side and resulting from damage to the R parietal.
1) Neurons become active long before they are fully developed, 2)
subsequent course of their development depends greatly on their activity
much which is triggered by external experience, 3) experience continuously
modifies genetic expression.
All behaviour is the product of interactions among three factors – 1) the
organism’s genetic endowment, 2) its experience, 3) its perception of the
Darwin was not the first to suggest that species evolve; undergo gradual
orderly change from preexisting species, but he was the FIRST to amass a
large body of supporting evidence and how evolution occurs.
1) Documented evolution of fossil records through recent geological layers,
2) Described stroking structural similarities among living species, 3) He
pointed to the major changes that had been brought about in domestic plants
& animals by programs of selective breeding.
Natural Selection: Evolution occurs through this, members of each species
vary greatly in their structure, physiology & behaviour and that the heritable
traits that are associated with high rates of survival & reproduction are the
most likely to be passed onto future generations.
Fitness: Ability of an organism to survive & contribute its genes to the next
Evolution & Behaviour
Social Dominance: The males of many species establish a hierarchy of social
dominance through combative encounters with other males – this is
important because dominant species copulate more than non-dominant ones.
Courtship Display: The male approaches the female and signals his interest.
Species: A group or organisms that is reproductively isolated from other
organisms that is reproductively isolated from other organisms – the PS263 – Chapter 2: Evolution, Genetics & Experience
members of a species can produce fertile offspring only by mating with
members of the same species.
Conspecifics: Members of the same species
Chordates: Animals with dorsal nerve cords; they are 1 of 20 or so large
categories of animal species. First developed with vertebrates were bony
fishes, today there are 7 categories, 3 fish, amphibian, reptiles, birds...etc.
Amphibians: Evolved 400 million years ago – frogs, toads, salamanders must
live in water as larva, until adults. (from fish to amphibians they evolved)
Reptiles: 300 million years ago evolved from amphibians – lizards, snakes
and turtles. First vertebrates to lay shell covered eggs and to be covered in
Mammals: Evolved 180 million years ago during the dinosaurs – the females
fed their young with secretions from special glands called mammary glands.
They laid their babies (no eggs) – only platypus is a mammal that lays eggs.
Primates: Apes are thought to have evolved from old-world monkeys – unlike
monkeys apes have NO TAILS.
Analogous: Structures that are similar but do not have a common
Homologous: Structures that are similar because they have a common
Convergent Evolution: The evolution in unrelated species of similar solution
to the same environmental demands - determines analogous/homologous.\
Evolution of human brain modern humans do not have the biggest
brains (1,350 grams) behind whales and elephants, no relationship between
the brain and intelligence; brain weight expressed as a % of total body weight
might be a better measure o