Aim: How is all life on Earth related? How did Darwin

change biology? Date: September 16, 2013

Catalyst: Dr. Dre is conducting an experiment to determine whether

listening to The Next Episode raises or lowers heart rates of listeners. How might

Dr. Dre design his experiment? What would the control be? What about the

independent and dependent variables?

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Agenda

• Levels of Organization

• Unity of Life

• Diversity of Life

• Pre-Darwinian Ideas

• Darwinian Revolution

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The Unity of Life

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The Unity of Life• 3 Domains

• Bacteria• Archaea• Eukarya

• Share traits, such as utilizing DNA to store genetic material.

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The Diversity of Life• Though life shares a common origin, there is

great diversity in form and function.

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Pre-Darwinian Ideas

• Aristotle

• Species were unchanging

• Linnaeus

• Grouped organisms by traits using binomial nomenclature

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Pre-Darwinian Ideas

• Lamarck

• Use and Disuse

• Inheritance of Acquired Characteristics

• Drive to become more complex

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Darwinian Revolution

• Charles Darwin

• Travelled on the HMS Beagle at the age of 22

• Naturalist surveying the South American Coast

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Darwinian Revolution

• Focus on adaptation - inherited characteristics that enhance survival and reproduction

• Natural Selection - Organisms better adapted to their environment tend to survive and produce more offspring.

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Darwinian Revolution

• Alfred Russel Wallace

• On the Origin of Species

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Darwinian Revolution

• Evolution- Descent with modification

• Artificial Selection - Selective breeding for individuals that possess desired traits.

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Darwinian Revolution

• Based his argument on the following observations:

1. There is variation in traits.

2. Species produce more offspring than the environment can support. Many of these fail to survive and reproduce.

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Darwinian Revolution

• From these observations, he inferred:

1. Those with traits that give a higher chance of survivng and reproducing leave more offspring.

2. Unequal ability of individuals to survive and reproduce will lead to accumulation of favorable traits in population.

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RED LIGHT

•In a few sentences, explain how Darwin’s work changed the world’s idea of how life on Earth came about.

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