10.1 Early Ideas About Evolution

1. 10.1 Early Ideas About Evolution

2. What is evolution? • Evolution is the process of biological change by which descendants come to differ from their ancestors. • Evolution is a central theme in all fields of biology today.

5. Charles Darwin • Natural selection was the theory he proposed to explain evolution. • He attempted to provide reasons for the biological diversity on Earth. • However, Darwin was not the first scientist to study evolution.

6. 4 Scientists before Darwin… • Carolus Linnaeus • Georges Buffon • Erasmus Darwin • Jean-Baptiste Lamarck

7. Carolus Linnaeus • In the 1700s, he developed a classification system to help organize all types of organisms into categories based on their similarities. • Scientists still use his classification system today.

8. Georges Buffon • He proposed that species shared ancestors rather than arising separately. • Species is a group of organisms so similar to one another that they can reproduce and have fertile offspring.

9. Erasmus Darwin • Charles Darwin’s grandfather • Proposed that all living things were descended from a common ancestor and that more-complex forms developed from less-complex forms

10. Jean-Baptiste Lamarck • He believed that species evolved into different forms rather than becoming extinct…flawed idea!

11. Jean-Baptiste Lamarck • He proposed the idea of inheritance of acquired characteristics: • changes in an environment caused an organism’s behavior to change • this would lead to greater use or disuse of a structure or organ. • the structure would become larger or smaller and would then be passed down to offspring • For example: giraffes’ long necks

13. So…. Darwin based his studies on the work of these four men and developed his theory known as evolution by natural selection.