1. Agenda
Warm-up
10.1 Preview
10.1 Fill-in Notes
Test Corrections

2. Warm-up
How could Evolution lead to this?!?!

3. OBJECTIVES
Examine early ideas about evolution
Identify three geological theories that influenced scientific debate over evolution

4. KEY CONCEPT There were theories of biological and geologic change before Darwin.

5. Vocabulary
Evolution - change in a species over time; process of biological change by which descendants come to differ from their ancestors. (298)
Species – group of organisms so similar to one another that they can breed and produce fertile offspring. (298)
Fossil – trace of an organism from the past. (300)

6. Vocabulary
Catastrophism – theory that states that natural disasters such as floods and volcanic eruptions shaped Earth’s landforms and caused extinction of some species. (301)
Gradualism - principle that states that the changes in landforms result from slow changes over a long period of time. (301)
Uniformitarianism – theory that states that the geologic processes that shape Earth are uniform through time. (301)

7. Types Genetic Variation
Recombination – new allele combinations form in offspring during Meiosis (sexual reproduction)
Independent Assortment
Crossing Over
Mutations – a random change in the DNA of a gene
Increase the genetic variation in the gene pool.
Happens in the reproductive cells.

8. Early scientists proposed ideas about evolution.
Evolution is the biological change process by which descendants come to differ from their ancestors.

9. There were many important naturalists in the 18th century.
Carolus Linnaeus: classification system from kingdom to species
Species – is a group of organisms so similar to one another that they can reproduce and have fertile offspring
George Louis Leclerc de Buffon: species shared ancestors rather than arising separately.
Buffon rejected the common idea of the time that Earth was only 6000 years old.

10. Eramus Darwin (Charles Darwin’s Grandfather): more-complex forms developed from less-complex forms
Jean-Baptiste Lamarck: environmental change leads to use or disuse of a structure
He believed that structures would become larger or smaller
Example: The long neck of giraffes evolved as generations of giraffes reached for leaves higher in the trees.

11. Theories of geologic change set the stage for Darwin’s theory.
There were three theories of geologic change.
George Cuvier: believed that species could not change over time, but could become extinct.
Fossils: traces of organisms that existed in the past.
Catastrophism: natural disasters such as floods and volcanic eruptions shaped landforms and caused species to become extinct.

12. James Hutton: Developed the theory of Gradualism.
Gradualism - changes occurred slow and over long periods of time.
Charles Lyell: Developed the theory of uniformitarianism.
Uniformitarianism – the geologic processes that shape Earth are uniform through time

13. Uniformitarianism is the prevailing theory of geologic change.