emily chpater 23 notes - Evolution acts on species even...

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Evolution acts on species even though it is populations that evolve Allele: eg. Blue eyes and brown eyes determined by different alleles Gene pool is twice the size of a population because everyone has two copies of an allele Natural selection acts on phenotype Natural selection can act on genes that vary so there has to be heterozygosity for variation in traits Mutations are the source of novel variations Mutations in somatic cells cannot be passed on to offspring Point mutation has to happen only once, but they often do not have a significant impact Repair mechanisms can help fix mutations If a protein function is inhibited, the organism cannot function Sometimes mutations improve fit between organism and its environment Only mutation—not sexual reproduction—creates new alleles, but sexual reproduction mixes alleles If a locus doesn’t vary in a population, it is considered fixed Natural selection can’t act based on fixed loci Hardy-Weinberg describes populations that are not changing—allele frequencies stay the same
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This note was uploaded on 01/25/2011 for the course BIO 1510 taught by Professor Unknown during the Spring '07 term at Georgia Institute of Technology.

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