ANTH205 Lecture 2 8 29 13 Lecture 2 Evolution Culture WHAT IS EVOLUTION o Change through time Adaptation to environment over time Evolution is the change in the frequency of particular genetic variants in a population over time MECHANISMS OF EVOLUTION o 1 Mutation Source of all variants random changes most are neutral or harmful o 2 Gene Flow o 3 Genetic Drift o 4 NATURAL SELECTION ONLY ONE CAPABLE OF INCREASING ADAPTIVE COMPLEXITY THEORY OF EVOLUTION BY NATURAL SELECTION THE NON RANDOM REPRODUCTION OF HERITABLE VARIANCE THREE KEY CONCEPTS 1 There exists variation in the population 2 This variation is heritable 3 Some traits will allow individuals to be more successful reproducers than others and these traits are passed on in greater numbers to subsequent generations Theory Of Evolution o Theory is a specific term in science Comprehensive explanation of important feature of nature that is supported by many facts gathered over time Examples Germ theory of disease Special theory of relativity Plate tectonic theory Atomic theory of matter o To be a successful theory IT MUST produce testable predictions FINDINGS PREDICTED BY THEORY OF EVOLUTION BY NATURAL SELECTION o 1 Common Ancestry We all come from common ancestors A We should find Transitional MISSING LINK Fossils THE FACT THAT WE HAVE HANDS AND PRIMATES DO TOO ETC DERIVED TRAITS ONLY SHARED BY HUMANS HUMANS HAVE A CONSCIENCE HUMANS WALK ON TWO LEGS HUMANS HAVE A VOICEBOX etc B Homology C Genetic Similarity D Embryology o 2 Population Changes Due to Changes in Selective Forces MICROEVOLUTION o 3 Genetic Selfishness Male lions killing baby cubs females still wanting a family with that male lion EVOLUTION THEORY DOES NOT SUGGEST o ALL adaptions appeared randomly o First reproducing entity was a cell o Complex parts of eye evolved simultaneously IS THERE A GENETIC COMPONENT TO BEHAVIOR o We have an infinite number of behavioral options There are a lot of things that we don t do because it simply doesn t make sense due to the fact that we have no desire to do certain things like eating dirt for example o How do we choose Through desires o Proximate means of achieving these goals are determined by experience culture etc o Ultimate goals desires fears o EMOTIONS The Genetic Component to Behavior Desires Hunger leads to the pursuit of food Tiredness Rest Sleep Cold Hot Shelter Clothes Water Libidinous Find Romantic Partner Loneliness Find Companionship Prestige Come to class Get a degree NATURE VS NURTURE o Common response by evolutionists to question of Is it nature or nurture YES o ALL THINGS BIOLOGICAL ARE PRODUCTS OF AN INTERACTION B T GENES AND THE ENVIRONMNET NATURALISTIC FALLACY o The confusion of what IS with what OUGHT to be Trying to define the world based on what it SHOULD be o Examples of the fallacy Results not showing total equality b t populations are wrong Certain crimes are justified due to biological roots 08 29 2013 08 29 2013