BNS midterm 2 10/9/2012 1:42:00 PM
CHAPTER TWO- Evolution
o Ex. Why do all humans show the same kind of facial expression to
communicate their different emotions?
Comparitive method precursors
o Ex. How does smiling develop, what behavioural stimuli induce it, what
parts of the brain are involved in production/recognition?
Face recognition neurons
Mirror neurons the basis of imitation
Zeitgeist: general intellectual climate of our culture which ingrains in our minds.
The biology of behaviour: dichotomies to interactions
Physiological or psychological:
o Cartesian dualism: the human mind and brain are separate entities
A category of human activity that somehow transcends the brain.
Assumption that some functioning is so complex it could not be a
product of the physical brain.
Ex. the man who fell out of bed
Asomoatognosia deficiency in the awareness of parts of
one's own body, usually from right parietal lobe damage.
all human experience, even very complex ones, can be
produced by manipulation of the brain.
Some nonhuman species (primates) have abilities that were
assumed to once be purely psychological/human.
Ex. self-awareness of chimps
Even non humans (no mind) are capable of psychological
complexity (self awareness)
Nature or nurture (learned/inherited)
o Ethology: The study of animal behaviour in the wild
o Instinctive behaviours: Behaviours that occur in all like species
Emphasized the role of nature, not just nurture.
o Progression of debate: 1 ) factors other than genetics/learning proved to influence
behaviour (broadened concept of nurture- included experience.)
2 ) behvaiour is result of nature & nurture combined.
Assumes they combine in additive fashion- not interaction.
Model of the biology of behaviour:
o all behaviour is the product of interaction of 3 factors:
1) genetics (product of evolution)
3) perception of current situation
o Evolve undergo gradual orderly change
o 3 kinds of evidence:
1) evolution of fossil records through more recent geog. layers.
2) Striking structural similarities between living species
yet differences too..
(evolving from common ancestors).
3) The major changes brought about in plants and animals through
of selective breeding. (artificial selection?)
o Natural selection heritable traits associated with high rates of survival
and reproduction are the most likely ones to be passed on.
Fitness the ability of an organism to survive and contribute its
genes to the next generation.
o scientific theory an explanation that provides the best current account
of some phenomenon based on the available evidence
evolution observed in progress:
o ex. peppered moth
before industrial revolution white form
after black form
o ex. darwins finches
summer of sever drought, only big seeds were left, average beak
Evolution over time: Early view:
o Greek philosopher Anaxiamander (611-547 B.C.)
o Greek philosopher Aristotle (384-322 B.C.)
o Roman philosopher Lucretius (99-55 B.C.)
o Scientist, Leonardo da Vinci (1452-1519)
o Physicist, Galileo Galilei (1564-642)
o Geologist, James Hutton (1726-1797)
o Geologist, Charles Lyell (1797-1875)
Evolution in 1700s:
o Georges-Louis Leclerc, Comte de Buffon:
The environment acts on organisms through "organic particles"
o Erasmus Darwin (Grandfather of Charles Darwin)
: Zoonomia, or The Laws of Organic Life
Species Change Position similar to Lamarks
Also: competition and sexual selection
Evolution in the 1800s
o Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck
1stcomprehensive theory of evolution
use and disuse leads to change
movement toward perfection
changes in form through conscious will
environmental effects on organ development
inheritance of acquired characteristics
ex. evolution of giraffes long neck (lamarcks view)
o Charles Robert Darwin
provided biology with its great unifying principle:
The Theory of Natural Selection
fossils in Patagonia
diversity of life in the Galapagos islands
Alfred Russel Wallace
wrote Letter to Darwin in 1858 with similar set of ideas. 3 observations & 2 deductions
Obs 1 Organisms have large capacity to overproduce.
Obs 2 Populations remain remarkably stable.
(with a few exceptions)
Ded 1 There is a struggle for survival.
Obs 3 Individuals differ in characteristics
many of these differences are heritable.
Ded 2 individuals with adaptive characteristics will
reproduce more successfully and will pass on these
characteristics to their offspring.
o (natural selection
Evolutionthe accumulation of the changes in the population due
to natural selection
ex. evoution of giraffes neck (darwins view)
o Neo-Darwinism in 1900s
darwins theory + heredity + Genetics
Fisher, Haldane, Wright
Fitnessthe ability of an organism to survive and to contribute its
genes to the next generation
Key Points on Evolution
o homologous structures (same) similar structures as result of same
(e.g. arm and bird wing)
convergent evolution the evolution in analogous species to the same
o analogous structures (similar) similar structures which dont have same
(e.g. bird and insect wings)
does not progress to preordained perfection
o very slow or with sudden changes
o Spandrelsevolutionary byproducts without a use.
e.g. belly button