Early Theories of Evolution

1. Early Theories of Evolution

2. Jean Baptiste de Lamarck • Scientist during the late 1700’s and early 1800’s • Among the first scientist to recognize that living things change over time • Attempted to explain how these adaptations • Lamarck was not generally respected in the scientific community and he died in poverty and obscurity

3. Darwin on Lamarck • Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801. . . he first did the eminent service of arousing attention to the probability of all changes in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition.

4. Lamarck’s Assumptions • Desire to Change • Believed that organisms had an inborn desire to better themselves and become better fit for their environments • Ex. Birds wanted to fly so over many generations they developed wings • Use and Disuse • Organisms could change the shape of structures by using them differently • Ex. Birds transformed front legs into wings by trying to use them to fly

5. One More Assumption • Passing on Acquired Traits • Lamarck believed that any traits that an organism had acquired over their life time would be passed on to their offspring • Ex. If a bird broke its wing all of its offspring would be born with a broken wing