Jan22anbhPOST - I. Another Example of Natural Selection II....

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I. Another Example of Natural Selection II. Recent History: Ethology and Comparative Psych. III. Tinbergen's Four Levels Of Analysis A. 4 Levels Defined B. Proximate/Ultimate Distinction C. Examples 1. fighting 2. why birds sing 3. more examples for practice
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A second N.S. example from http://www.abc.net.au/science/news/stories/s1688507.htm Darwin's Finches Evolving Fast by Larry O'Hanlon 17 July 2006 A Galapagos finch that helped reveal the origins of species to Charles Darwin has now undergone a spurt of rapid climate-driven evolution, biologists report. The medium ground finch ( Geospiza fortis ), of Daphne Island was nudged, and then shoved, to evolve a smaller beak. This happened by the combination of competition from another finch that arrived on the island more than 20 years ago and more recent drought conditions. "It happened very fast," says biologist Professor Peter Grant… The evolutionary nudging began when some larger finches settled on Daphne during an exceptionally wet El Niño in 1982. In the years since, the larger G. magnirostris finches have been eating most of the larger, thorny seeds of the island's puncture vine plants and steadily pushing the smaller finches to rely on smaller seeds from other plants
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As a result, G. fortis birds with smaller beaks that did not compete with the larger birds did better, and were more likely to have offspring. That essentially enriched the gene pool with small beak genes and led to more G. fortis with smaller beaks. But the matter really came to a head in 2003 and
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This note was uploaded on 04/22/2008 for the course PSYC 2074 taught by Professor Kurthoffman during the Spring '08 term at Virginia Tech.

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Jan22anbhPOST - I. Another Example of Natural Selection II....

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