Charles Darwin - wrote On the Origin of Species
- contemporaries believed that species were unchangeable, structures made due to will of the Divine Creator
- proposed that natural laws produced change/evolution over time
- never challenged the existence of a Divine Creator
- based his ideas on studies in S America and Galápagos Islands
- didn't publish his results for 16 years until Alfred Russel Wallace submitted similar theory independently
- The Descent of Man - argues that humans and apes have similar ancestors
Darwin's evidence - from expeditions to the Americas
- fossils of extinct armadillos found in the same area where similar armadillos lived
- 14 species of finches on the Galápagos Islands all had different beaks from eating different food, but otherwise very similar
- resemblances in plants in close areas, not similar climates
Thomas Malthus - wrote Essay on the Principle of Population
- pointed out that human population grew geometrically, but food supply grew arithmetically
- only death prevents populations from growing out of control
- his ideas made Darwin realize that only organisms w/ superior attributes survive
natural selection - survival of the fittest; environment only allows the best fit to survive
- artificial selection - breeders selecting specific organisms to pass along desired characteristics
- organisms ill-suited for the environment die out; their attributes don't get passed on
evidence of evolution after Darwin - more support for evolution has come up since his time
- fossil record - goes back 2.5 billion years; shows how organisms changed from simple to complex
- age of the earth - estimated to be 4.5 billion years; people of Darwin's time thought the earth was only a few thousand years old
- genetics - explains how new variations occur in organisms
- comparative anatomy - limbs and appendages of different organisms containing the same type of bones
- homologous bones - have same evolutionary origin, but have different uses
- analogous bones - have similar structure but different evolutionary origins
- molecular evidence - more closely related organisms have less differences in DNA
- molecular clock - constant change that occurs to proteins over time
- phylogenetic tree - pattern of descent that maps out the history of an organism
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