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COMPLETE THE
EVOLUTION SURVEY
EVOLUTION
Accumulation of inherited changes within a
population over time
2 types of evolution
Microevolution
Macroevolution
Pre-Darwinian Ideas
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Darwin was not 1st to propose theory of
evolution
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Aristotle (4th century BC)
◦ Life extended from simple to complex
◦ Imperfect but moving toward perfection
◦ No mechanism for HOW
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Jean Baptiste de Lamarck (1744-1829)
◦ 1st to propose that organisms undergo change over
time as a result of natural phenomena
◦ Use and disuse
◦ Theory of acquired characteristics
◦ LAMARCK WAS WRONG IN MECHANISM
Charles Darwin

Influenced by:
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Voyage of Beagle
Geology: Hutton & Lyell
Thomas Malthus (economist)
Artificial Selection
Darwin’s key contribution:
◦ Mechanism
◦ How evolution occurs
Darwin’s Theory of Evolution by
Natural Selection

In struggle for survival, favorable traits
preserved, unfavorable ones eliminated
◦ Adaptation

Natural Selection – best adapted
organisms survive and pass on their
traits, population changes over time
◦ Fitness
4 aspects of natural world on which
Darwin based his theory:
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Overproduction
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Variation
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Limits on population growth
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Differential reproductive success
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http://www.pbs.org/wgbh/evolution/library
/11/2/quicktime/e_s_4.html
What Natural Selection is NOT:
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Natural Selection is not a CHOICE
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Natural Selection is NOT BASED ON NEED
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Natural Selection is not a MUST
Modern Synthesis
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Mendel’s work (1860s) not recognized
until 20th century
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1930s-40s – biologists combined
Mendelian inheritance with Darwinian
Evolution
◦ Mutations are source of variation
◦ Continue to try to understand causal
processes of evolution
Some new perspectives on
Evolution…
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EvoDevo
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Epigenetics