E. Dilemmas

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E. Dilemmas 1. Evolution of complex traits

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E. Dilemmas 1. Evolution of complex traits

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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms?
X
X
X
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X
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• E. Dilemmas
• 1. Evolution of complex traits
• 2. Where are the continuous sequences of
  transitional forms?
• the fossil record is incomplete not all species
  leave a fossil
• Keep looking

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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms? 1861 Archeopteryx
Lithographica
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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms? 3. What is the source
of heritable variation???
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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms? 3. What is the source
of heritable variation??? - Natural selection
should weed out poorly adapted forms over time,
making the organisms in the population more
similar (less variation). Why is there still so
much variation in natural populations?
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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms? 3. What is the source
of heritable variation??? - selection should
eliminated variation - and if heredity is
governed by blending traits, then how is
variation produced generation after generation?

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E. Dilemmas 1. Evolution of complex traits 2.
Where are the continuous sequences of
transitional forms? 3. What is the source
of heritable variation??? - selection should
eliminated variation - and if heredity is
governed by blending traits, then how is
variation produced generation after generation?
- Darwins explanation - Lamarckian use and
disuse, and gemmules
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F. Darwinian Evolution 1. Darwins Model Sources
of Variation Causes of Change ????????????????
? VARIATION ? NATURAL SELECTION (use and
disuse??)