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BEHAVIOR WITHOUT LEARNING Evolution and Development Chaos Theory and Darwin ’ s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection
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BEHAVIOR WITHOUT LEARNING Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection Addendum: 3A. Phylogeny, Ontogeny and Behavior
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection
Evolution is a name for something that happens. It is not a theory. • Darwin’s account is a theory about why evolution happens. • Some history: Other theories of evolution and the eclipse of Darwinism: • Lamarckism • Orthogenesis • Mendelian genetics • The Modern Synthesis: Mendelian genetics, Darwinian selection, and mutation research
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection; Sexual Selection The Origins of Complexity Evolution and Development Kinds of Selection
Variability and selection go hand in hand -- you cannot have one without the other • Once variability is created, change (evolution) follows • Selection, whether in phylogeny or in ontogeny or in cultural practices, will happen
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity: e.g., the eye Evolution and Development Kinds of Selection
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development: Evo-Devo Kinds of Selection
Evolution and Development • Chaos Theory and Darwin’s Butterfly • The Nature of Evolution • Recipes and Blueprints • Variation and Selection • The Origins of Complexity • Evolution and Development: Evo-Devo • Modules, Boundaries, and Genetic Switches • Kinds of Selection
Evolution and Development • Chaos Theory and Darwin’s Butterfly • The Nature of Evolution • Recipes and Blueprints • Variation and Selection • The Origins of Complexity • Evolution and Development: Evo-Devo • Modules, Boundaries, and Genetic Switches • Epigenetics • Kinds of Selection
Evolution and Development Chaos Theory and Darwin’s Butterfly The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection
Three Varieties of Selection Natural or Phylogenic Selection Selection by the environment of populations of organisms (and therefore populations of genes) Operant or Ontogenic Selection Selection of behavior by its consequences within the lifetime of the individual organism Cultural or Memetic Selection Selection of behavior as it is passed on from one organism to another
Three Varieties of Selection • Phylogenic (Darwinian selection) • Ontogenic (operant selection) • Cultural (memetic selection) • The three varieties may work in concert or in opposition to one another (consider drugs as reinforcers in ontogeny, but with deleterious effects at the other levels of selection). • Scenarios about human origins (including the evolution of verbal behavior) must take all three levels into account.
Selection for Variationin Behavioral and Biological Systems • We will see later that variability itself can be selected. There are advantages to variability: for example, coming up with effective new responses in unusual environments • A parallel in biology is that species otherwise seeming similar in phenotype can vary in their genetic diversity, and those with the greater genetic diversity have selective advantages over the others, especially in the face of changing environments. A substantial research literature supports this conclusion.
What are the implications? • A wider range of variations makes a population more viable under changing contingencies. Species at risk are especially those in very specialized environments. • These populations may exist at any level of selection: phylogeny, ontogeny, or culture (though selection at one level need not support selection at another). • Species, behavior patterns and cultures that include many variations may have advantages over those that are less flexible.
Historical Challenges • Variations are essential to selection • Darwinian thinking went through an eclipse • The source of novelty was the issue: Mendelian genetics couldn’t provide it. • Mutation research made the difference. • There was a parallel challenge, especially from linguistics, to behavioral thinking, which is now emerging from its eclipse. • In that case too, sources of novelty were the issue: How can children say novel things they’ve never heard before?
Evolution and Development The Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development Kinds of Selection