recap to this point Empirical Unanswered questions Unanswered - - PowerPoint PPT Presentation

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• Empirical

Empirical foundations foundations

• change & time

change & time

• How and Why?

How and Why?

• Charles Darwin

Charles Darwin (1809 (1809– –1882) 1882)

• Darwin

Darwin’ ’s three s three postulates postulates

1.

• 1. “

“struggle for struggle for existence existence” ”

2.

• 2. variation and natural

variation and natural selection selection

3.

• 3. inheritance

inheritance

• Unanswered questions

Unanswered questions

• genetics =

genetics =

• mutation =

mutation =

• What about behavior?

What about behavior?

• culture =

culture =

• cultural variation =

cultural variation =

• innovation =

innovation =

• adaptation =

adaptation =

• biological adaptation

biological adaptation

• cultural adaptation

cultural adaptation

• cultural

cultural uniformitarianism uniformitarianism

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change was big & occurred change was big & occurred in regular sequence in regular sequence Thomsen & Thomsen & Worsaae Worsaae enough time for change in enough time for change in human life human life-

• ways

ways Boucher Boucher enough time for change enough time for change Lyell Lyell life is changeable life is changeable Linnaeus Linnaeus

recap to this point

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Linnaeus Lyell Boucher, Thomsen & Worsaae

How and Why does life change?

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Charles Darwin in 1880

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Theory of Evolution Theory of Evolution Darwin Darwin’ ’s Three Postulates s Three Postulates

1. 1.

More offspring are produced than can More offspring are produced than can survive survive

2. 2.

Organisms are variable in the traits that Organisms are variable in the traits that affect their survival affect their survival

3. 3.

Traits that affect survival are inherited by Traits that affect survival are inherited by

• ffspring
• ffspring

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• populations grow to carrying capacity (K)

populations grow to carrying capacity (K)

• K = the number of individuals that an

K = the number of individuals that an environment can support environment can support

population size time

K

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• more offspring produced than can survive

more offspring produced than can survive

• ffspring produced in excess of K
• ffspring produced in excess of K must

must die to die to bring the population back into equilibrium bring the population back into equilibrium

population size time

K

Malthusian Principle

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• K = 100 individual

K = 100 individual

• 50 offspring are produced

50 offspring are produced

• 25 adults die at end of generation

25 adults die at end of generation

• 25 offspring in excess of K

25 offspring in excess of K must must die die

• Which 25?

Which 25?

population size time

K

Malthusian Principle Calculus of Survival

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Theory of Evolution Theory of Evolution Darwin Darwin’ ’s Three Postulates s Three Postulates

1. 1.

More offspring are produced than can More offspring are produced than can survive survive

2. 2.

Organisms are variable in the traits that Organisms are variable in the traits that affect their survival affect their survival

3. 3.

Traits that affect survival are inherited by Traits that affect survival are inherited by

• ffspring
• ffspring

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• +

number of individuals innate flu resistance

Populations are variable!

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• +
• +

Survivors change in environment

How variation affects survival (natural selection = …)

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Theory of Evolution Theory of Evolution Darwin Darwin’ ’s Three Postulates s Three Postulates

1. 1.

More offspring are produced than can More offspring are produced than can survive survive

2. 2.

Organisms are variable in the traits that Organisms are variable in the traits that affect their survival affect their survival

3. 3.

Traits that affect survival are inherited by Traits that affect survival are inherited by

• ffspring
• ffspring

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• +

Survivors produce new offspring

Variation and reproduction For evolution to occur, new

• ffspring MUST inherit the traits that

allowed their parents to survive

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• +

flu resistance number of individuals

• ffspring well-fit (adapted)

to new environment

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• +

Survivors

• +
• ffspring poorly fit to environment

(adapted) and most will die

What if a trait is inherited randomly, or is not heritable at all?

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• +

flu resistance number of individuals

• ffspring well-fit (adapted)

to new environment

IS THIS PROGRESS? DIRECTIONAL CHANGE TOWARDS A PERFECT ORGANISM?

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• +
• +
• +

generation 1 generation 2 generation 3

Equilibrium

• +
• +
• +

generation 1 generation 2 generation 3

Fluctuating Environment

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Darwin Darwin’ ’s Unanswered Questions s Unanswered Questions

• How are biological traits inherited?

How are biological traits inherited?

• genetics = inheritance of biological information

genetics = inheritance of biological information

• How does new biological variability arise?

How does new biological variability arise?

• mutation = generation of new biological

mutation = generation of new biological variability variability

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What about behavior? What about behavior?

• Most behaviors are non

Most behaviors are non-

• genetic!!!

genetic!!! Preferences: EMINEM v. Coltrane?

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• How is behavioral information inherited?

How is behavioral information inherited?

• Culture

Culture = system for inheritance of behavioral = system for inheritance of behavioral (non (non-

• genetic) information

genetic) information

• = social learning

= social learning

• = learned behavior

= learned behavior

• Cultural Variation

Cultural Variation = differences in the = differences in the behaviors expressed by individuals as a result behaviors expressed by individuals as a result

• f different social learning opportunities
• f different social learning opportunities

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• +

number of individuals Eminem Fan Factor

Behavior is Variable & Influences Survival

different social learning opportunities

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dietary preferences dietary preferences

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• How is new culture generated?

How is new culture generated?

• Innovation

Innovation = = “ “a change in the way of doing a change in the way of doing something something” ”

• Innovation by accident = Errors

Innovation by accident = Errors

• analogous to genetic mutation

analogous to genetic mutation

• Innovation by design = Intentional change

Innovation by design = Intentional change

• ften called
• ften called “

“Invention Invention” ”

• no close analogy in biology (in a pre

no close analogy in biology (in a pre-

• bioengineering world)

bioengineering world)

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• Adaptation

Adaptation

= characteristics of an organism that evolved = characteristics of an organism that evolved through natural selection and which result in a through natural selection and which result in a “ “good fit good fit” ” between the organism and the between the organism and the environment environment

• Biological adaptation

Biological adaptation

= genetically = genetically-

• based characteristics of an

based characteristics of an

• rganism
• rganism…

…

• Cultural adaptation

Cultural adaptation

= behaviorally = behaviorally-

• based (non

based (non-

• genetic) characteristics

genetic) characteristics

• f an organism
• f an organism…

…

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biological adaptation in Gazella subgutturosa (goitered gazelle)

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• cultural adaptation =

cultural adaptation =

Inuit seal hole hunting Aztec human sacrifice

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• cultural/biological uniformitarianism?

cultural/biological uniformitarianism?

• biological, behavioral and cultural processes observed

biological, behavioral and cultural processes observed today also operated in the past today also operated in the past

• cultural

cultural uniformitarian uniformitarian calculations? calculations?

• minor cultural process x long time = BIG RESULT

minor cultural process x long time = BIG RESULT

• minor innovations applied to existing systems x

minor innovations applied to existing systems x … …= = … …

Wight Bros., December 17, 1903 Boeing 747, December 17, 2003