Asexual Hermaphroditic

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Asexual/ Hermaphroditic

• WFSC 422 Ethology
• Presentation 8.3

Dr. Jane M. Packard, WFSC TAMU j-packard_at_tamu.edu
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What are alternatives to bisexual reproduction?

• Asexual
• No recombination of DNA
• Clones- exact copies
• Hermaphroditic
• Each individual produces both sperm and eggs-
  recombinant DNA
• Both male female behavior (simultaneous or
  sequential)

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Example- sea louse
Source Courting Trials of life
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Other species- asexual

• Hydra
• Daphnia
• aphids

(source Drickamer et al. 2001)
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Example- giant clam
Source Courting Trials of life
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FUNCTION

• H1 Rapid reproduction in short-term optimal
  conditions (ocean, pond, plant)
• H2 Reproduction not dependent on presence of
  opposite sex (patchy habitat, small populations)

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UE phylogenetic history

• One-celled organisms
• Ancestral- evolved in ocean
• Derived- adapted to freshwater ponds
• Derived- switch from asexual to sexual
• Multiple-celled organisms
• Ancestral- bisexual reproduction
• Derived- parthenogenesis

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SUMMARY alternatives to bisexual strategies

• Function
• H1 rapid reproduction in short term optimal
  conditions (e.g. hydra, daphnia, aphids)
• H2 reproduction in patchy, small populations
  (giant clam)
• Evolution
• H1 1-celled oceanic ancestorgt freshwater ponds
• H2 multi-celled bisexual ancestorgt
  parthenogenesis

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Action Items

• Do answers for Q8.5, Q8.6
• Search idealibrary for asexual
• Search Animal Behavior for hermaphroditic
• Post examples and sources on WebCT Discussion for
  Unit 8