The Evolution of Evolution

Consider…  10:30 pm on December 31: the first human-like animals emerge  Modern-looking humans have only been around for 100,000 years

Evolution  Pre-Darwin  Plato and Aristotle  Carolus Linnaeus ( )

Jean-Baptiste Lamarck ( )  Continual adjustment  Ideas were flawed

Lamarck vs. Darwin

Georges Cuvier ( )  Catastrophism  i.e., Noah ’ s flood

Sir Charles Lyell ( )  Geological change was slow and continual, not due to catastrophes  uniformitarianism  Corresponded with Darwin

Alfred Russel Wallace ( )  Reached similar conclusions as Darwin

Charles Darwin ( )

The Voyage of the HMS Beagle Galapagos Islands

The Principles of Natural Selection According to Darwin 1. Variation  The essential underlying feature of evolution  Random mutations create a variety of individuals, some of whom are better suited to the environment

The Principles of Natural Selection According to Darwin 2. Heritability  Offspring inherit characteristics from their parents

The Principles of Natural Selection According to Darwin 3. Differential Reproductive Success  “Natural Selection”  Those who inherit favorable characteristics will thrive  Those who do not will die out

British Moths and Kettlewell ’ s Experiment

Directional vs. Normalizing Selection  Directional: adaptation toward an adaptive change  i.e., the peppered moth  Normalizing: adaptation against extremes  i.e., birth weight

Evolution After Darwin  “Punctuated Equilibrium”  Stephen Jay Gould  The mapping of the human genome has changed everything  Genetic mutation is not the only element of change  “ Switch ” Genes