BEHAVIOR WITHOUT LEARNING

Evolution and Development

Chaos Theory and Darwin’s ButterflyThe 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 ButterflyThe 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 ButterflyThe 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 ButterflyThe 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 ButterflyThe 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 ButterflyThe 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 ButterflyThe 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 ButterflyThe Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development: Evo-Devo

Modules, Boundaries, and Genetic SwitchesKinds of Selection

Evolution and Development

Chaos Theory and Darwin’s ButterflyThe Nature of Evolution Recipes and Blueprints Variation and Selection The Origins of Complexity Evolution and Development: Evo-Devo

Modules, Boundaries, and Genetic SwitchesEpigenetics

Kinds of Selection

Evolution and Development

Chaos Theory and Darwin’s ButterflyThe 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 SelectionSelection 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 organismCultural or Memetic Selection

Selection of behavior as it is passed on from one organism to another

- 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.

Three Varieties of Selection

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