Some evolution concepts

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Some evolution concepts
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Anagenesis Yes, but not this example!
Implications
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Contrast of two ideas about the fundamental basis
of change
Principles of 1) use and disuse 2) inheritance of
acquired characteristics
Principle of Natural selection Variation
present before it would be of value.
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Transformational evolution Lamarck
Variational evolution Darwin
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1798
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Example of an adaptation. Giraffe neck
size Why do giraffes have Long necks? Set up
an hypothesis.
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Evidence
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• Why do giraffes have long necks?
• There was (is) a difference in neck size among
  bulls.
• Competition for females during a brief
  reproduction season. Males engage in combat
  necks are used.
• Neck length accompanied by a gain in mass
• Sexual selection males with stronger necks have
  greater mating success.
• Alleles resulting in stronger necks tend to be
  passed on to progeny and increase in the
  population.
• The population changes over time.
• Peacock tails?