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Unformatted text preview: due to soot. The once rare dark-colored moths became more prevalent, while the once-common light-colored moths became increasingly rare. Reason: predation by birds. The color that had the greatest contrast with the background (tree trunk) was at a disadvantage. Cleanup of the forest during the 1950s caused the allele frequencies of light and dark moths to reverse to pre-Industrial Revolution levels, dark moths are now rare, light moths are now common. The resistance of many bacterial species to antibiotics ia another example of directional selection. Over 200 speciews show some degree of antibiotic resistance, necessitating the development and more prudent use of a new generation of antibiotic medicines....
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This note was uploaded on 11/29/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.
- Fall '10