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Chapter 1: How Evolution Works. What is Biological Anthropology? 4 fields Cultural or Social Archaeology Linguistics Biological or Physical Anthropology Body Growth Nutrition Primatology Molecular/Genetics Paleoanthropology Applied. Adaptation. What is an Adaptation?
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Chapter 1: How Evolution Works • What is Biological Anthropology? • 4 fields • Cultural or Social • Archaeology • Linguistics • Biological or Physical Anthropology • Body • Growth • Nutrition • Primatology • Molecular/Genetics • Paleoanthropology • Applied
Adaptation • What is an Adaptation? • Structures that are designed by Natural Selection • Adaptations provide solutions to evolutionary problems (survival and reproduction). • Evolutionarily Stable Problems. • Best thought of in terms of function.
Function: • Ultimate: Why Question! • To make copies of itself, Reproductive Success (RS) • Proximate: What Question! • What does the adaptation do?
Darwin’s Three Postulates • 1. The ability of a population to expand is infinite, but the ability of any environment to support populations is always finite. “THE STRUGGLE FOR EXISTENCE.” • 2. Organisms within populations vary and this variation affects the ability of individuals to survive and reproduce. “DIFFERENTIAL REPRODUCTIVE SUCCESS” • 3. The variations are transmitted from parents to offspring. “SEX”
Units of Selection • Selection takes place at the level of Individuals • Selection does not take place at the level of Groups or Populations • Adaptations change through time not individuals or population • Vehicles vs. Units of Selection
Inheritance of Traits • Blending Inheritance • Mixing of traits undoes natural selection • Discreet Units of Inheritance • Necessary to maintain adaptations (design features of traits)