Upload
lorraine-montgomery
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
Ch. 14.1: Darwin developed a Theory of EvolutionObjectives1. Summarize ideas from
Darwin’s time that influenced his work.
2. Identify some key observations from Darwin’s voyage that led to his theory.
3. Describe the two main points of Darwin’s theory.
Vocabulary
Evolution
Adaptation
Descent w/ Modification
Natural selection
What do you know about the Theory of Evolution?
Do you agree or disagree?
• Humans evolved from apes.
What do you know about the Theory of Evolution?
Do you agree or disagree?
2. Individual organisms can evolve.
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.
What do you know about the Theory of Evolution?
Do you agree or disagree?
4. Evolution can happen in one life time.
What do you know about the Theory of Evolution?
Do you agree or disagree?5. Evolution can only happen over millions of
years.
What do you know about the Theory of Evolution?
Do you agree or disagree?
6. Humans have stopped evolving.http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#a8
http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#a8
Old IdeasBefore 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!)
Lamarck’s Theory of EvolutionInheritance of Acquired
Characteristics
Based on 3 Ideas
1. Desire (will) to change
2. Use and Disuse
3. Passing on acquired traits
Introduces idea that populations CAN EVOLVE or CHANGE (correct)
Knew NOTHING about GENES/GENETICS.
Charles DarwinProposed 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.
2. NATURAL SELECTION = mechanismWell suited individ. SURVIVE & REPRO. More offspring (pass genes on)
Darwin’s ObservationsVoyage 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
Evolution by Natural Selection
1. Wild species show variations (due to genetics)
2. High birthrates & limited resources cause competition (everyone can’t survive & thrive)
3. Individuals well-suited to enviro. SURVIVE & REPRO. (SURVIVAL OF FITTEST)
4. Larger portion of each new generation will have favorable variation.
5. Over long periods of time, small changes accumulate (Adaptation occurs!)
6. Environment “chooses” favored traits (Selective Pressure)
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
http://www.aurumscience.com/biology/11_evolution/great_transformations.html
Self Quiz 1. 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.