Your Inner Fish ch 9 - JBHA-Sci-US-tri1

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Transcript Your Inner Fish ch 9 - JBHA-Sci-US-tri1

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Your Inner Fish by Neil Shubin
Chapter 9: Vision
Rebecca Saionz
AP Bio – 9/13/10
What do humans and Old World
monkeys have in common?
• Detailed kind of color vision
– Three different kinds of light receptors, each
attuned to a different kind of light
– Other mammals only have two
– Allows us to distinguish more colors
http://http://pin.primate.wisc.edu/fs/sheets/images/510med.jpg
What is the benefit of color vision?
• This kind of color vision arose about 55 million
years ago
• Fossil evidence from this same time reveals
changes in Earth’s flora
– greater diversity of plants, likely with different
colors
http://upload.wikimedia.org/wikipedia/commons/1/1e/Cones_SMJ2_E.svg
The Genes Responsible for Vision
• The Drosophila eyeless gene
The mouse Pax 6 gene
– “Master control” for the development/formation
of eyes
– Mutation can cause ocular defects, producing
creatures with small eyes or no eyes at all
http://www.developmentalbiology.net/images/ectopic-eyes.jpg
http://www.elconfidencial.com/fotos/salud/2008050267aniridiaDentro_20080503.jpg