Transcript Chapter 1 Historyx

A History of
Behavioural Ecology
The Greeks
• Plato (on the left)
– Mind-body dichotomy
– Knowledge comes
from reason
• Aristotle
– Intellect is
metaphysical
– Knowledge comes
from learning laws of
nature
Skip forward 2000 years…
• Descartes
–17th century
–Cartesian dualism
–Humans alone have souls
–Animals are automata
Life: Is it special?
• Turn of the 19th Century
• Vitalists
– Vital Spark
– Therefore, life is not
strictly subject to laws of
physics etc.
• Mechanists
– All natural things
(including life) have
physical causes
http://www.craphound.com/images/insectlab07.jpg
Early Mechanists
• Loeb
– Tropism
• E.g., positive phototaxis
– Took it way too far
• Pavlov
– Classical conditioning
• Conditioned stimulus
– The bell
• Unconditioned stimulus
– The food
– Again, way too far
The Naturalists
• 1500-1700’s
• Non-scientific catalogues of
animal habits
• Buffon’s Histoire Naturelle
(1749) argues behaviors are
taxonomic characters
• Instinctivists: Vitalist-like
naturalists
– Used anecdotal evidence to
construct a theory of instinct
http://www.lewisclark.org/media/NewImages/PHILADELPHIA/paleo_
Buffon-port-Drouais.jpg
The Advent of
Evolutionism
• The watch on the heath
• Jean-Baptiste Lamarck
– Student of Buffon
– A mechanist
– Over long time scales,
species spread to fill
space, adapt to local
environments
http://www.biografiasyvidas.com/biografia/l/fotos/l
amarck.jpg
Lamarck’s Theory I
• Two forces
– Complexifying force
• Simple creatures are formed by spontaneous
generation, of course
• Drives all living things up the ladder of
progress
• Works by laws of alchemy
– The rapid motion of fluids will etch canals between
delicate tissues. Soon their flow will begin to vary,
leading to the emergence of distinct organs. The
fluids themselves, now more elaborate, will become
more complex, engendering a greater variety of
secretions and substances composing the organs. Histoire naturelle des animaux sans vertebres 1815.
– Adaptive force
• Modified animals to fit their environment
according to the law of use and disuse
http://img.sparknotes.com/figures/1/153432
7ece5d347f8fe2828c8fdb7677/giraffe.gif
Lamarck’s Theory II
• The Law of Use and Disuse
– In every animal which has not passed the limit of its development, a more
frequent and continuous use of any organ gradually strengthens, develops and
enlarges that organ, and gives it a power proportional to the length of time it has
been so used; while the permanent disuse of any organ imperceptibly weakens
and deteriorates it, and progressively diminishes its functional capacity, until it
finally disappears.
• Modifications were passed on by soft inheritance
– The heritable basis of the character is based on something other than random
mutation (widely believed before Lamarck)
– All the acquisitions or losses wrought by nature on individuals, through the
influence of the environment in which their race has long been placed, and hence
through the influence of the predominant use or permanent disuse of any organ;
all these are preserved by reproduction to the new individuals which arise,
provided that the acquired modifications are common to both sexes, or at least to
the individuals which produce the young.
• Lamarck’s contributions
– Coherent Theory of Evolution
– Adaptation to the environment plays a central role
Charles Darwin
• 1859 The Origin of Species by Means of Natural Selection
• All organisms derived from a common ancestor
• Natural Selection drives adaptive evolution
–
–
–
–
If there is variability…
… and heritability
… and a consistent relationship between the trait and reproduction
… then adaptive’ traits will be disproportionately represented in the
next generation (hence evolution by natural selection)
• Did not understand genetic basis of inheritance
• Darwinism vs. Lamarckism
– Variation and the environment
– Chance vs. ordered progression
Darwin & Behaviour
• Behavior responds to selection
• Humans are part of the
continuity of animal evolution
– The basis of Comparative
Psychology
• Animals may have mental
processes
• Sexual selection
– Two main mechanisms
• Male-male competition  size,
weaponry
• Female choice  ornamentation
Comparative Psychology
• Romanes (1882)
– Subjective inference:
• … I found a [few ants] passing along at intervals. I confined one of these
under a piece of clay at a little distance from the line, with his head
projecting. Several ants passed it, but at least one discovered it and tried to
pull it out, but could not. It immediately set off at a great rate, and I thought it
had deserted its comrade, but it had only gone for assistance, for in a short
time about a dozen ants come hurrying up, evidently fully informed of the
circumstances of the case, for they made directly for their imprisoned
comrade and soon set him free. I do not see how this action could be
instinctive. It was sympathetic help, such as man only among the higher
mammalia shows. The excitement and ardour with which they carried on
their unflagging exertions for the rescue of their comrade could not have
been greater if they had been human beings.
This observation seems unequivocal as proving fellow- feeling and
sympathy, so far as we can trace any analogy between the emotions of the
higher animals and those of insects.
The Behaviourist Approach
• A branch of Comparative Psycholgy
• Morgan, Thorndike, & Skinner
• Morgan
– Promoted observational method
– “Subjective induction”
– Morgan’s cannon
• In no case may we interpret an action as the outcome of
the exercise of a higher psychical faculty, if it can be
interpreted as the outcome of the exercise of one which
stands lower in the psychological scale.
– A linear psychological scale?
Edward Thorndike
• Early 20th century
experimentalist
• Puzzle boxes
– Result
– Behaviorist interpretation
• Impulsive struggle
• Success  “Stamping In”
• Law of Effect
– Results modify behavior; strength
of effect determines strength of
modification, reward and
punishment both work
• Law of Exercise
– Repetition improves the
connections
B.F. Skinner
• Operant boxes
• Operant conditioning
– Stimulus 
Behavioral response
 reinforcement 
learning to modify
response
– Endlessly contrasted
to classical
conditioning
http://upload.wikimedia.org/wikipedia/co
mmons/e/e4/Skinner_box.png
Summary of Behaviourism
• It’s all about stimulus and response
– Contrast with Naturalism
• Laws vs. variations
• Mental processes are unimportant /
unknowable
• Animals are models of human behavior
• Emphasize acquired behavior
• Skeptical, parsimonious
• Highly experimental
Ethology
• Early 20th Century
• Emerged from Biology
• Evolution-based study of the natural behavior
of animals in the wild
– Contrast with Comparative Psych.
• Emphasized learning, domestic animals, mechanistic
explanations
• Believed that instincts
could evolve
– Grebe courtship
Niko Tinbergen
• Nifty experiments on wild
animals
–Black-headed gull egg study
• Observed that females remove
shells
–Animals tell you the questions
• Anti-predation hypothesis & test
Tinbergen’s four causes
• Proximate causes
–Immediate causation
(mechanism)
–Ontogeny (development)
• Ultimate causes
–Evolution
–Function (adaptive value)
Konrad Lorenz
• Imprinting
– An instinct for learning!
– Critical period
– Affects filial attachment and
sexual behaviour
• Fixed action patterns (FAPs)
– Elicited by innate releasing
mechanisms
• Motivational states as a
function of action specific
energy
– Is this real???
The Ethologist’s approach to
adaptationism
• Relied on goodness of fit between
the behaviour and the environment
• Failed to integrate Modern Synthesis
of Darwin and Population Genetics
• Applied good of the species
arguments
The advent of Behavioural
Ecology
• 1975 Publication of EO Wilson’s
Sociobiology
–How do population parameters (incl.
ecology, genetics) affect the evolution
of behavior?
• Increasing reliance on mathematical
models of behavioral evolution
W.D. Hamilton
• Kin selection
– Altruism (selfsacrifice) can
be adaptive
and spread in a
population
when givers
and receivers
are close
relatives
http://www.healthline.com/blogs/outdoor_health/uploaded_image
s/bee-stinger-724392.jpg
Robert Trivers
• Reciprocal
altruism
http://news.rutgers.edu/focus/issue.2007-0124.1635050508/article.2007-01-24.1096980350/photo
http://www.zoo.cam.ac.uk/zoostaff/
BBE/Radford/Andy3.htm
John Maynard Smith
• Borrowed game theory
modeling from economics
–Allows consideration of
fitness value of a
behavioral strategy given
the frequency of various
strategies in the population
Richard Dawkins
• 1976 The Selfish Gene
–Popularized and clarified
the idea that selection
acts to maximize selfreplication at the genetic
and individual levels
• …but not so much at the
population or species levels
http://upload.wikimedia.org/wikipedi
a/en/a/a5/Dawkinssouthpark.jpg
Behavioral Ecology
• The emergent field
– The interaction between animals and
their environment (incl. social)
– Strong focus on adaptation
– Specific mathematic models
– Hypothesis driven
• Desire to generalize
• First ISBE meeting in 1986