1. 15.2 – Ideas That Shaped Darwin’s Thinking

2. Darwin’s Ideas
Darwin greatly changed the thinking of many scientists, but also many did not believe him
Most Europeans at the time believed Earth was only created a few thousands of years before present time
They believed everything was created the way it was and never changed
By the time Darwin set sail there was a rich fossil record challenging this idea

3. Lamarck’s Theory of Evolution
One of first scientists to recognize things have changed over time
He also recognized organisms were adapted to their environment
He proposed that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime
And then be inherited

4. Lamarck’s Examples

5. Lamarck’s Theory of Evolution
Section 15-2
Fiddler Crab example
2. Use and disuse
Waving to attract mates
Tendency towards perfection
Changing to live more successfully
3. Inheritance of acquired characteristics

6. Lamarck’s Theory His theory is incorrect in several ways
He was one of the first to develop the Theory of Evolution and realize animals adapt to their environment

7. Population Growth
In 1798, Thomas Malthus saw babies were being born faster then people were dying
He reasoned if that continues to happen the time might come when there is insufficient land and food on Earth to support the population size
Does this apply to all living organisms?