Alpine Sky Pilots - measuring strength of selection

Alpine Sky Pilots - measuring strength of selection - ◙...

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Darren Rothberg Biol 105 – Evolution Alpine Sky Pilot: Polemonium viscosum Rocky Mountain wildflower Near the timberline: pollinated by flies, small solitary bees and some bumblebees Higher tundra: bumblebees are only pollinators Flowers here are 12% larger than at timberline Large flowers attract more bumblebees The question: how long would it take to increase flower size 12% starting with the smaller-flowered timberline population? Measured flowers of 144 small-flowered timberline plants Germinated in lab and transplanted in parental habitat 7 years later had 58 blooming offspring
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Unformatted text preview: ◙ Heritability estimated as between 0.2 and 1.0 Measuring strength of selection differential ⇒ Placed 98 Sky Pilots from a small-flowered timberline population in large screened cages that kept bumblebees and other pollinators out ⇒ Measured flowers later and collected seeds ⇒ Planted seedlings from these seeds in parental habitat ⇒ Used the number of progeny from each plant flowering six years later to measure ⇒ Plants with large corollas have greater fitness than those with smaller corollas ◙ Selection gradient = 0.13...
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This note was uploaded on 04/24/2008 for the course BIOL 103 taught by Professor Foster during the Fall '08 term at Clark University.

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