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Galapogas Islands

Galapogas Islands - identify them at one point banded every...

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Anthropology Movie “Beak of the Finch” Galapogas Islands: 18 islands, all but 5 inhabited. 1977: probed by 100s of scientists, traversed by tourists Darwin: no less than 6 species of finches with different beaks. Peter and Rosemary Grant (modern): came back to GI to measure and catalogue beaks over past 20 years. - Daphne Major: field study of Darwin’s finches Finches not afraid of humans, no predators (occasional owl…) largest threat is the weather. Vary in size from 3-6 inches. Vary in color. Mating: Male sings, some mate for life, some have up to 11 different mates. Males help feed young to imprint his song. Finches have adapted to eat food on the islands, no two have the same beak. Beak for cactus, or stripping tree bark, getting seeds. 13 variations in beaks. Rarely compete for food. Initially only two species on the island : cactus finch, medium ground finch <- more interesting one. Enormous variation. Catalogue the deaths, births, matings, courtings and eating patterns of the birds. Began to band them to
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Unformatted text preview: identify them at one point banded every finch on the island (over 1000). Know histories of all the birds. Darwin: 5 years of the Beagle, under Captain Fitzroy. Object of the mission: continue survey of S. America region and Tiara Del Fuego. Evolution = natural selection + genetics (variation) Darwin thought it takes millions of years; Grants prove it doesnt. Hybridizing: mating with large and small beak species. Results in the medium ground finch to have greater variety of beaks. Recently: up to 50% of the birds dying. Due to starvation, lack of rain = lack of food. Not as bad as drought in 1977 no rain for over 500 days. By sampling seeds they could tell which seeds were disappearing and which seeds the birds were turning to. small beaked birds couldnt crack the remaining large seeds, large beaked birds survived. Natural selection operates under extreme conditions....
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