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 instincthttp://www.lewis-clark.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/lamarck.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/1/1534327ece5d347f8fe2828c8fdb7677/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/commons/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 (self-sacrifice) can be adaptive and spread in a population when givers and receivers are close relatives http://www.healthline.com/blogs/outdoor_health/

uploaded_images/bee-stinger-724392.jpg

Robert Trivers

http://www.zoo.cam.ac.uk/zoostaff/BBE/Radford/Andy3.htm

• Reciprocal altruism

http://news.rutgers.edu/focus/issue.2007-01-24.1635050508/article.2007-01-24.1096980350/photo

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 self-replication at the genetic and individual levels• …but not so much at the

population or species levelshttp://upload.wikimedia.org/

wikipedia/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