� Empirical Empirical � Unanswered questions Unanswered questions recap to this point � foundations foundations foundations foundations � genetics = � genetics = genetics = genetics = � change & time change & time Lyell Lyell enough time for change enough time for change � mutation = mutation = Young Earth & Fixity of Life � How and Why? � How and Why? How and Why? How and Why? � What about behavior? � What about behavior? What about behavior? What about behavior? � � � Charles Darwin Charles Darwin � culture = culture = Linnaeus Linnaeus life is changeable life is changeable ( (1809–1882) (1809 1882) ) � cultural variation = � cultural variation = cultural variation = cultural variation = � Darwin’s three Darwin’s three � innovation = innovation = p postulates postulates Boucher Boucher enough time for change in enough time for change in g g g g � adaptation = � adaptation = adaptation = adaptation = � � human life- human life -ways ways 1. “struggle for “struggle for 1. � biological adaptation biological adaptation existence” existence” � cultural adaptation � cultural adaptation 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 uniformitarianism uniformitarianism Worsaae Worsaae Worsaae Worsaae in regular sequence in regular sequence in regular sequence in regular sequence 3. inheritance inheritance i h it i h it 3. 1 2 recap to this point Lyell Lyell enough time for change enough time for change Linnaeus Linnaeus life is changeable life is changeable Boucher Boucher enough time for change in enough time for change in g g g g human life- human life -ways ways Lyell Linnaeus Boucher, Thomsen & Worsaae & Worsaae Thomsen & Thomsen & change was big & occurred change was big & occurred How and Why does life change? How and Why does life change? Worsaae Worsaae Worsaae Worsaae in regular sequence in regular sequence in regular sequence in regular sequence 3 4
June 23, 1831 Ch Charles Darwin in 1880 l D i i 1880 (1809-1882) 5 6 On the Origins of Species by Means of Natural Selection On the Origins of Species by Means of Natural Selection Theory of Evolution Theory of Evolution Darwin’s Three Postulates Darwin’s Three Postulates � published in 1859 published in 1859 More offspring are produced than can More offspring are produced than can 1. 1. survive survive � first comprehensive first comprehensive theory of evolution theory of evolution Organisms are variable in the traits that Organisms are variable in the traits that 2. 2. affect their survival affect their survival � very controversial very controversial Traits that affect survival are inherited by Traits that affect survival are inherited by � proven largely correct proven largely correct 3. 3. offspring offspring 7 8
K K size size pulation pulation Malthusian Principle pop pop time time � populations grow to carrying capacity (K) populations grow to carrying capacity (K) l ti l ti t t i i it (K) it (K) � more offspring produced than can survive more offspring produced than can survive � K = the number of individuals that an K = the number of individuals that an � offspring produced in excess of K offspring produced in excess of K must p p g p g p must die to die to environment can support environment can support i bring the population back into equilibrium bring the population back into equilibrium 9 10 on size Theory of Evolution Theory of Evolution K populatio Darwin’s Three Postulates Darwin’s Three Postulates Malthusian Calculus of Survival P i Principle i l p More offspring are produced than can More offspring are produced than can 1. 1. survive survive time time � K = 100 individual K = 100 individual Organisms are variable in the traits that Organisms are variable in the traits that g 2. 2. � 50 offspring are produced 50 ff 50 offspring are produced 50 ff i i d d d d affect their survival affect their survival � 25 adults die at end of generation � 25 adults die at end of generation 25 adults die at end of generation 25 adults die at end of generation Traits that affect survival are inherited by Traits that affect survival are inherited by 3. 3. � 25 offspring in excess of K 25 offspring in excess of K must must die die offspring offspring p p g g � Which 25? Which 25? 11 12
How variation affects survival dynamically Populations are variable! p (natural selection � of survivors) als dividua change in environment r of ind number n + + - - - + + innate flu resistance innate fl resistance Survivors 13 14 Theory of Evolution Theory of Evolution Variation and reproduction Darwin’s Three Postulates Darwin’s Three Postulates Survivors Survivors More offspring are produced than can More offspring are produced than can 1. 1. produce survive survive new offspring new offspring Organisms are variable in the traits that Organisms are variable in the traits that g 2. 2. affect their survival affect their survival + - For evolution to occur, new Traits that affect survival are inherited by Traits that affect survival are inherited by 3. 3. offspring offspring p p g g offspring MUST inherit the traits that p g allowed their parents to survive 15 16
What if a trait is inherited randomly, or offspring well-fit (adapted) is not heritable at all? i t h it bl t ll? to new environment uals ndividu er of in numb - + - + Survivors - + flu resistance offspring poorly fit to environment offspring poorly fit to environment (adapted) and most will die 17 18 Equilibrium IS THIS PROGRESS? DIRECTIONAL CHANGE TOWARDS DIRECTIONAL CHANGE TOWARDS A PERFECT ORGANISM? offspring well-fit (adapted) + + + - - - to new environment als generation 1 generation 1 generation 2 generation 2 generation 3 generation 3 dividua r of ind Fl Fluctuating Environment i E i number - + n - + + - + + - + + flu resistance generation 1 generation 2 generation 3 19 20
What about behavior? What about behavior? Darwin’s Unanswered Questions Darwin’s Unanswered Questions � Most behaviors are largely non Most behaviors are largely non- -genetic!!! genetic!!! � How are biological traits inherited? How are biological traits inherited? � genetics system for the inheritance of � genetics = system for the inheritance of genetics = system for the inheritance of genetics system for the inheritance of biological information biological information � How does new biological variability arise? How does new biological variability arise? � mutation = generation of new biological � mutation = generation of new biological mutation = generation of new biological mutation = generation of new biological variability variability Music Preferences? 21 22 Behavior is Variable & May Influence � How is behavioral information inherited? � How is behavioral information inherited? How is behavioral information inherited? How is behavioral information inherited? Survival S i l different social different social ls ividual � Culture C l C l Culture = system for inheritance of behavioral = system for inheritance of behavioral f f i h i i h i f b h f b h i i l l learning opportunities (non (non- -genetic) information genetic) information r of ind � = social learning = social learning � = learned behavior = learned behavior umber � Cultural Variation � Cultural Variation Cultural Variation = differences in the Cultural Variation = differences in the differences in the differences in the nu behaviors expressed by individuals as a result behaviors expressed by individuals as a result of different social learning opportunities of different social learning opportunities of different social learning opportunities of different social learning opportunities + + - E Eminem Fan Factor i F F t 23 24
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