How large should offspring be

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How large should offspring be?

• Trade-off between number and size of offspring.
• Produce many small OR few large?
• Can be dictated by the environmental context
  i.e., the reproductive strategy may include
  phenotypic plasticity
• e.g. A seed beetle

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Seed beetle Stator limbatus
Blue palo verde seed Poor host lt 1/2 larvae
survive
Cat-claw acacia seed Good host most larvae
survive
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The model Size decreases with an increased
number of sibs
Minimum size at which offspring survive is
smaller on good host
Offspring survival
Optimal offspring size for parent is larger on
poor host
Parental fitness
Prediction larger eggs on poorer host
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Restricted to one host
1st egg on on host - then switched
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• A fitness enigma 1999

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Karyotype of Aspidoscelis neotesselata
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A. neotesselata (17.0 mL)
A. sexlineata (7.1 mL)
A. tesselata (24.2 mL)
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2006 resolution
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2
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Altricial birds asynchronous hatching

• Selective brood reduction
• Counters the unpredictability of resources
• Size range
• Releasers and responses
• Effects

Siblicide