2. Evolution Ideas That Shaped Darwin’s Thinking

3. At the time… Most people believed the Earth was only a few thousand years old Most believe species and the Earth has NEVER changed Most, but not all! New fossil evidence begins to shift many people’s veiwpoints

4. Geology Perspective Hutton- proposed that Earth changes over time, including the rock cycle and other natural forces shape the earth; proposed the Earth is millions of years old Lyell- proposed how volcanoes and other geologic forces can build and destroy landscapes

5. Darwin’s Take… Darwin thought if the Earth could change, why couldn’t life change? Also, if the Earth is changing, plants and animals MUST change to survive! This begins his new theory of evolution.

6. Economy/Ecology Perspective Malthus: reasoned that if the human population continued to grow unchecked, food and shelter will run out (carrying capacity) This idea alone sprung forth the steps to natural selection.

7. Other Evolution Hypotheses Lamarck: stated that selective use or disuse of organs causes organisms to acquire or lose certain traits… Then, these traits can be passed on to offspring Ex:Crab Claw Is this a valid hypothesis? Can you think of your own example?