recap to this point Empirical � Unanswered questions Unanswered questions Empirical � � � foundations foundations � genetics = genetics = � Linnaeus life is changeable � change & time change & time Linnaeus life is changeable � mutation = mutation = � � How and Why? How and Why? � What about behavior? What about behavior? � � � � Charles Darwin Charles Darwin � culture = culture = � � Lyell enough time for change Lyell enough time for change (1809– (1809 –1882) 1882) � cultural variation = cultural variation = � Darwin’ Darwin ’s three s three � � � innovation = innovation = � postulates postulates Boucher enough time for change in Boucher enough time for change in � adaptation = adaptation = � 1. “ “struggle for struggle for human life- -ways ways human life 1. � biological adaptation biological adaptation � existence” ” existence � cultural adaptation cultural adaptation � 2. variation and natural variation and natural 2. � cultural cultural Thomsen & Thomsen & change was big & occurred change was big & occurred selection � selection uniformitarianism uniformitarianism Worsaae Worsaae in regular sequence in regular sequence 3. inheritance inheritance 3. 1 2 Linnaeus Lyell Boucher, Thomsen & Worsaae How and Why does life change? Charles Darwin in 1880 3 4
Theory of Evolution Theory of Evolution K Darwin’ ’s Three Postulates s Three Postulates Darwin population size More offspring are produced than can More offspring are produced than can 1. 1. survive survive Organisms are variable in the traits that Organisms are variable in the traits that 2. 2. affect their survival affect their survival time Traits that affect survival are inherited by Traits that affect survival are inherited by 3. 3. � populations grow to carrying capacity (K) populations grow to carrying capacity (K) � offspring offspring � K = the number of individuals that an K = the number of individuals that an � environment can support environment can support 5 6 population size K K Malthusian population size Calculus of Survival Principle Malthusian Principle time � K = 100 individual K = 100 individual � � 50 offspring are produced 50 offspring are produced � time � 25 adults die at end of generation 25 adults die at end of generation � � more offspring produced than can survive more offspring produced than can survive � � 25 offspring in excess of K 25 offspring in excess of K must must die die � � offspring produced in excess of K offspring produced in excess of K must must die to die to � bring the population back into equilibrium bring the population back into equilibrium � Which 25? Which 25? � 7 8
Theory of Evolution Theory of Evolution Populations are variable! Darwin’ ’s Three Postulates s Three Postulates Darwin More offspring are produced than can More offspring are produced than can number of individuals 1. 1. survive survive Organisms are variable in the traits that Organisms are variable in the traits that 2. 2. affect their survival affect their survival Traits that affect survival are inherited by Traits that affect survival are inherited by 3. 3. offspring offspring + - innate flu resistance 9 10 Theory of Evolution Theory of Evolution How variation affects survival (natural selection = …) Darwin Darwin’ ’s Three Postulates s Three Postulates More offspring are produced than can More offspring are produced than can 1. 1. change in environment survive survive Organisms are variable in the traits that Organisms are variable in the traits that 2. 2. affect their survival affect their survival Traits that affect survival are inherited by Traits that affect survival are inherited by 3. 3. offspring offspring - + - + Survivors 11 12
Variation and reproduction offspring well-fit (adapted) to new environment number of individuals Survivors produce new offspring + - For evolution to occur, new - + flu resistance offspring MUST inherit the traits that allowed their parents to survive 13 14 IS THIS PROGRESS? What if a trait is inherited randomly, or DIRECTIONAL CHANGE TOWARDS is not heritable at all? A PERFECT ORGANISM? offspring well-fit (adapted) number of individuals to new environment - + + - Survivors offspring poorly fit to environment - + flu resistance (adapted) and most will die 15 16
Equilibrium 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 � - + - + - + generation 1 generation 2 generation 3 � How does new biological variability arise? How does new biological variability arise? � � mutation = generation of new biological mutation = generation of new biological � variability variability Fluctuating Environment - + + - + - generation 1 generation 2 generation 3 17 18 What about behavior? What about behavior? � How is behavioral information inherited? How is behavioral information inherited? � � Most behaviors are non Most behaviors are non- -genetic!!! genetic!!! � � 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 of different social learning opportunities of different social learning opportunities Preferences: EMINEM v. Coltrane? 19 20
Behavior is Variable & Influences dietary preferences dietary preferences Survival different social number of individuals learning opportunities + - Eminem Fan Factor 21 22 � How is new culture generated? How is new culture generated? � Adaptation Adaptation � � = characteristics of an organism that evolved = characteristics of an organism that evolved � Innovation Innovation = = “ “a change in the way of doing a change in the way of doing � through natural selection and which result in a through natural selection and which result in a something” something ” “good fit “ good fit” ” between the organism and the between the organism and the environment environment � Innovation by accident = Errors Innovation by accident = Errors � � Biological adaptation Biological adaptation � analogous to genetic mutation � analogous to genetic mutation � = genetically- -based characteristics of an based characteristics of an = genetically � Innovation by design = Intentional change Innovation by design = Intentional change � organism… organism … often called “ “Invention Invention” ” � often called � � no close analogy in biology (in a pre no close analogy in biology (in a pre- - � Cultural adaptation Cultural adaptation � � bioengineering world) bioengineering world) = behaviorally- -based (non based (non- -genetic) characteristics genetic) characteristics = behaviorally of an organism… of an organism … 23 24
� cultural adaptation = cultural adaptation = � Inuit seal hole hunting biological adaptation in Gazella subgutturosa Aztec human sacrifice (goitered gazelle) 25 26 � 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 uniformitarian uniformitarian calculations? calculations? � cultural � 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 27
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