New Topics

1
New Topics

• Coevolution
• special case between interdependent species
• Study examples in Pollination Biology
• best understood examples of coevolution
• Focus on Role of Natural Selection

2
COEVOLUTION

• Coevolution reciprocal change driven by the
  interaction of 2 or more species.
• Arms race Plant/Herbivore
• Mutualism symbiotic specialization
• Geographic Mosaic Theory
• Modern synthesis by John N. Thompson and others.

Gilia tricolor
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Pollination

• Pollination Has 3 Components
• 1.) Receipt of genes (?)
• 2.) Delivery of genes (?)
• 3.) Pollination Vector
• Wind or Animal

Gilia tricolor
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How do Pollinators and Flowers affect each other?

• Flowers
• Optimize pollination
• Minimize costs
• make it hard to get pollen Nectar
• Maximize rewards
• receive enough of correct pollen

• Pollinators
• Optimize feeding
• Minimize costs
• feed easily
• Maximize rewards
• eat enough pollen or nectar to more than
  compensate for their effort

5
Pollination Syndromes

• Under right conditions pollinators can exert
  selection pressures on floral traits, resulting
  in floral morphology and structure that may be
  adaptations to maximize efficiency of
  pollination.
• Flowers that are specialized for specific
  Pollinators Have a distinct morphology.

6
Pollination Syndromes

• Bird Great sight! Poor smell.
• Floral traits
• Odorless
• Large
• Tubular
• Often red
• Large nectaries

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Jewelweed, Impatiens sp Nat. Hist. 5/99.
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Aquilegia formosa
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Pollination Syndromes

• Bats very poor sight, very good smell.
• Floral traits
• Strong odors musky or fruity
• large
• dull colors white or green
• often only open at night.

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Stenocerus thurberi with Leptonycteris curasoae
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Pollination Syndromes

• Bees good sense of sight, smell ok.
• Floral traits
• Blue or yellow (yellow blue in UV specturm)
• Distinctive markings honey guides path to
  nectaries.
• Landing pads.

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Bee Vision in UV
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Rosemarinus officinalis with Apis mellifera
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Digitalis purpurea
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Natural Selection Force?
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Natural Selection Force?
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Direction of Selection Force
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3 types of Selection Forces
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References

• http//elib.cs.berkeley.edu/photos/flora/
• Ethan J. Temeles and Paul W. Ewald. 1999.
  Fitting the Bill? Natural History.
  5(March)52-55.
• John N. Thompson. 1994. The Coevolutionary
  Process. The University of Chicago Press,
  Chicago. p376.
• Peter H.Raven, Ray F. Evert and Susan E.
  Eichorn. 1999. Biology of Plants. W.H.
  Freeman and Company, New York. P944.
• Scott A. Hodges and Michael L. Arnold. 1994.
  Floral and ecological isolation between
  Aquilegia formosa and A. pubuscens. Proc.
  Natl. Acad. Sci. 912493-2496.
• Teresa Audesirk and Gerald Audesirk. 1999.
  Biology Life on Earth (5th ed). Prentice-Hall
  Upper Saddle River, NJ. P890.

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Review of Previous Topics

• Evolution by Natural Selection.
• Survival of the Fittest much more.
• Three types of Selection Forces
• Stabilizing
• Disruptive
• Directional