1 The Evidence for Evolution Chapter 22. 2 Darwin’s Finches.
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Transcript of 1 The Evidence for Evolution Chapter 22. 2 Darwin’s Finches.
1
The Evidence for Evolution
Chapter 22
2
Darwin’s Finches
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Peppered Moths and Industrial Melanism
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Selection Against Melanism
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Artificial Selection
• Agriculture– corn kernel characteristics
6
Artificial Selection
• Domestication– breeds and characteristics of dogs
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Evidence for Evolution
The Fossil Record
Anatomical Record
Molecular Record
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History of Life
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The Evolution of Horses
• Modern members of Equidae (horses, zebras, donkeys) are descendents of a lineage originating in the Eocene period 55 mya.
– The earliest known members were species in genus Hyracotherium. small size multiple toes small, simple teeth
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The Anatomical Record
• Homology– structures with different appearances and
functions that all derived from a common ancestor
– Development– different organisms exhibit similar
embryological forms
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The Anatomical Record
• Vestigial structures– organs with no apparent modern function,
but resemble ancestral structures
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The Molecular Record
• Distantly related organisms are expected to accumulate a greater number of evolutionary differences than closely related species.
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Convergent Evolution
• Convergent evolution - selection that favors changes making two or more groups more similar
– similar solutions to similar problems
• Divergent evolution - selection that favors changes making two or more groups less similar
– exposure to different selective pressures
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Convergent Evolution
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Darwin’s Critics
• there are no fossil intermediates• natural selection does not imply evolution
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Summary
• Beaks of Darwin’s Finches• Peppered Moths and Industrial Melanism• Artificial Selection• The Fossil Record• The Anatomical Record• The Molecular Record• Convergent and Divergent Evolution