Ch 24 - The Origin of Species (1 slide per page)-1

G insects penis are custom shaped insects eg flowers

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Unformatted text preview: 8th ed) e.g. insects penis’ are custom shaped Insects e.g. Flowers may be isolated if their pollinators are differently shaped 29 29 Prezygotic Reproductive Barriers 5. Gametic isolation gametes meet but no zygote formed External fertilization: gametes don’t recognize each other Internal fertilization: sperm can’t penetrate egg or is killed prior to trying 30 30 Postzygotic Reproductive Barriers 1. Reduced hybrid viability Hybrid embryo dies 31 31 Postzygotic Reproductive Barriers 2. Reduced hybrid fertility • Offspring healthy but usually sterile due to different chromosome numbers • Male zebra + female donkey zedonk 32 32 Postzygotic Reproductive Barriers 3. Hybrid breakdown • 1st generation viable and fertile • 2nd generation feeble or sterile e.g. various rice species 37 37 Humanzees ?!!! Chimps (Pan paniscus) is 99.4% genetically similar to humans “Ape woman” Actually: Human w/ Hypertrichosis Julia Pastrana Mexican-Indian (1834-1860) “Ape man – Oliver” Actually: Male chimpanzee 39 39 Pr...
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