1. Ch. 14.1: Darwin developed a Theory of Evolution
Objectives
Summarize ideas from Darwin’s time that influenced his work.
Identify some key observations from Darwin’s voyage that led to his theory.
Describe the two main points of Darwin’s theory.
Vocabulary
Evolution
Adaptation
Descent w/ Modification
Natural selection

2. What do you know about the Theory of Evolution?
Do you agree or disagree?
Humans evolved from apes.

4. What do you know about the Theory of Evolution?
Do you agree or disagree?
2. Individual organisms can evolve.

5. What do you know about the Theory of Evolution?
Do you agree or disagree?
3. Populations will evolve adaptations that they need to be successful.

6. What do you know about the Theory of Evolution?
Do you agree or disagree?
4. Evolution can happen in one life time.

7. What do you know about the Theory of Evolution?
Do you agree or disagree?
5. Evolution can only happen over millions of years.

8. What do you know about the Theory of Evolution?
Do you agree or disagree?
6. Humans have stopped evolving.

9. Old Ideas Darwin’s Influences Before Darwin
Species are fixed or permanent
Earth was less than 10,000 years old (and unchanging)
Darwin’s Influences
Lyell: Study of fossils and rock record … Earth is much older than 10,000 and Earth CHANGES.
Farmers: Selective breeding can change species.
Malthus: Economist (Famine & disease result when population are bigger than resources. Selective pressure)
Lamarck (1800): Inheritance of Aquired Characteristics (Organisms can adapt!)

10. Lamarck’s Theory of Evolution
Inheritance of Acquired Characteristics
Based on 3 Ideas
Desire (will) to change
Use and Disuse
Passing on acquired traits
Introduces idea that populations CAN EVOLVE or CHANGE (correct)
Knew NOTHING about GENES/GENETICS.

11. Charles Darwin Proposed THEORY OF EVOLUTION.
1. Descent with Modification
Change in species over time.
Modern organisms descend from ancient.
Adaptations are acquired in response to changes in habitat
Adaptation: Inherited trait that improves ability to survive & repro.
NATURAL SELECTION = mechanism
Well suited individ. SURVIVE & REPRO. More offspring (pass genes on)

12. Darwin’s Observations
Voyage on the BEAGLE
Galapagos:
Unique organisms - similar to, but different from plants on nearest mainland.
Each island had in chain had some different species.
Mainland species had changed after they colonized the islands and adapted to new environments.
Wrote: On Origin of Species (w/ Wallace), 1858

13. Unique Species of Galapagos

14. Evolution by Natural Selection
Wild species show variations (due to genetics)
High birthrates & limited resources cause competition (everyone can’t survive & thrive)
Individuals well-suited to enviro. SURVIVE & REPRO. (SURVIVAL OF FITTEST)
Larger portion of each new generation will have favorable variation.
Over long periods of time, small changes accumulate (Adaptation occurs!)
6. Environment “chooses” favored traits (Selective Pressure)

15. Peppered Moths: Natural Selection in Action
Which one is best “fit” for the environment?
What happened?
Relative frequency of alleles for color changed in the gene pool for the population.
Why?
Change in selective pressure

16. Self Quiz
You hear someone remark that evolution says we come from monkeys. Educate them with your response.
2. Discuss 1 influence (person) on the development of Darwin’s theory. Explain HOW this influence relates to Darwin’s EVOLUTION.

17. Self Quiz What did Lamarck get right? What did he get wrong?
4. 2 Sentence Summary: What is evolution and how does it work?