1 animal behavior: why (and how) do animals do what they do? picture: animal cognition.net

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Animal Behavior: Why (and how) do animals do what they do?

Picture: Animal cognition.net

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Aristotle (384-322 B.C.): Observational work in zoology

Embryology

Anatomy

Characteristics: Vivipary

Behavior: Social organization

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5/13/08: Natural Selection and History of Animal Behavior

Lecture objectives:

1. Understand Darwin’s theory of evolution by natural selection

2. Identify the major people and questions that guided the development of the modern study of animal behavior

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The views on relationships between species have progressed over time

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Darwin set the stage for the study of animal behavior through his theory of natural selection

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Evolution by natural selection is inevitable if 3 conditions are met:

1. Variation:

2. Heredity:

3. Differences in reproductive success:xxSurvival of the “fittest”

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Evolution by natural selection acts at the genetic level

Peppered moth:Gene for color

has two alleles (forms): R, r

RR, Rr

rr

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Example of natural selection in action: moths in England during the Industrial Revolution

I tawt I taw a peppered

moth!

Brown trunks increase

Proportion of light moths

0

1

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What would a population look like over timeif one of Darwin’s 3 conditions is not met?

1. No Variation?

2. No Heredity?

3. No Differences in reproductive success?

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Biologists often seek to understand behavior through the lens of natural selection

“How does this trait promote reproductive success?”Logic:

Conditions of n.s. apply to

So species have been

So the traits we observe today are a

So these traits probably exist because

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Example of Darwinian approach: How does infanticide by male langurs increase the male’s reproductive success?

x x

Tendency for infanticide

No tendency for infanticide

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Example of Darwinian approach: Why might a (former) mother langur be willing to mate with this new male?

x

Tendency to mate

No tendency to mate

x

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How might building an elaborate bower enhance the reproductive success of male bowerbirds?

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The history of the study of animal behavior

Aristotle Darwin

PavlovThorndike

Skinner

Lorenzvon FrischTinbergen

Behaviorism

Ethology

ModernAnimal

Behavior

1900

1973

Nobel Prize

350 B.C. 1859

ComparativePsychology

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Pavlov: Classical Conditioning

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Thorndike and Skinner: Operant Conditioning

(Trial-and-error learning)

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The history of the study of animal behavior

Aristotle Darwin

PavlovThorndike

Skinner

Lorenzvon FrischTinbergen

Behaviorism

Ethology

ModernAnimal

Behavior

1900

1973

Nobel Prize

350 B.C. 1859

ComparativePsychology

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Karl von Frisch: Communication & Sensory abilities in Honeybees

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Konrad Lorenz (1903-1989): Instinct, Imprinting & Motivation

Form of imprinting:“Westermarck effect”

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Niko Tinbergen (1907-1988): What features of the environment do animals respond to?

Sign stimuliAggression in 3-spined sticklebacks

Fixed action patternsEgg-rolling behavior in

graylag geese

Experiments!

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Behaviorist or Ethologist? You decide!

“Give me a dozen healthy infants…and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select – doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors.”

?

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Behaviorist or Ethologist? You decide!

His view: Each animal has its own subjective universe, or way of sensing the world around it. And as a consequence, different animals, even ones that share the same physical environment, might have unique sensory experiences.

?

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The history of the study of animal behavior

Aristotle Darwin

PavlovThorndike

Skinner

Lorenzvon FrischTinbergen

Behaviorism

Ethology

ModernAnimal

Behavior

1900

1973

Nobel Prize

350 B.C. 1859

ComparativePsychology

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The modern study of animal behavior is a synthesis of behaviorism and ethology

Behaviorists came to recognize that

Ethologists came to recognize that

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The history of the study of animal behavior

Aristotle Darwin

PavlovThorndike

Skinner

Lorenzvon FrischTinbergen

Behaviorism

Ethology

ModernAnimal

Behavior

1900

1973

Nobel Prize

350 B.C. 1859

ComparativePsychology

Context: Biology - Evolution “Nature”

Fieldwork: Insects, bird, fish

Context: Psychology - Learning “Nurture”

Labwork: Mammals, Pigeons

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Darwin discussion

1. Variation: What might maintain this?

2. Heredity: Are all traits hereditary?

3. Differences in reproductive success:

What might make some animals be less successful at producing offspring?

xx