Supplementary videos

Hermaphrodite flatworms mating (penis fencing)
Hermaphrodite leopard slugs mating in midair
Meiosis, crossing over, and the SRY gene: XX males and XY females (HHMI)
Sponges spawn without mating rituals
Surinam toad exhibits maternal care
Giant Pacific Octopus is devoted mom (BBC Life 3:00-5:55)

Extra credit readings

• Social hierarchies: Size and growth modification in clownfish Nature 7/10/03
• Bird sex gene found The Scientist 8/26/09
• No final answers yet on sex determination in birds Nature 11/5/09
• Mouth-brooding frog is Species of the Day! Zoological Society of London 4/12/10
• Indonesia's birth control pill for men GlobalPost 2/27/11
• Fecal Transplants: They Work, the Regulations Don’t Wired.com 12/9/11
• What Fixes Low Testosterone Best: Meds or Porn? Newsweek 5/20/09
• In Ducks, War of the Sexes Plays Out in the Evolution of Genitalia New York Times 5/1/07
• Study links estrogen exposure to fish kills, disease Greenwire 6/4/09

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