1. Descent with Modification – A Darwinian View of Life
Chapter 22
Descent with Modification – A Darwinian View of Life

2. Endless Forms Most Beautiful
African beetles beat the heat in the Sahara desert - BBC wildlife

3. Key Observations About Life
1. the striking ways in which organisms are suited for life in their environments
2. the many shared characteristics of life
3. the rich diversity of life

4. Evolution Descent with modification
A change in the genetic composition of a population form generation to generation

5. The Darwinian revolution challenged traditional views of a young Earth inhabited by unchanging species
Aristotle( B.C.) – “scale of nature”
Each form perfect and permanent
Coincided with ideas from the Old Testament

6. 1700’s
Carolus Linnaeus – nested classification system and binomial system of naming

7. Ideas About Change over Time
Paleontology – study of fossils

8. Catastrophism

9. Uniformitarianism

10. Lamarck’s Hypothesis of Evolution
Fossil evidence  Life was not fixed Life evolves as environment changes
Mechanisms explaining how evolution occurs

11. Descent with modification by natural selection explains the adaptations of organisms and the unity and diversity of life
Galapagos Finches – Could new species arise from an ancestral form by the gradual accumulation of adaptations to a different environment?
Natural selection – a process in which individuals with certain inherited traits leave more offspring than individuals with other traits