Evolution, 4th Edition

variation at those sites is eliminated. Polymorphism remains, however, at regions farther away on the chromosome. This distincti ...

120 CHAPTER 5 debilitating condition called sickle-cell anemia, which drastically decreases sur- vival. But the S allele has not ...

Futuyma Kirkpatrick Evolution, 4e Sinauer Associates Troutt Visual Services Evolution4e_05.19.ai Date 12-13-2016 20 40 60 80 100 ...

122 CHAPTER 5 We can use that formula and the data on survivorship to predict how the allele frequencies will evolve. The data s ...

THE GENETiCAl THEoRy of NATuRAl SElECTioN 123 change depending on their own frequencies. In some cases, an allele gets a fit- ne ...

124 CHAPTER 5 Genetic variation that is maintained this way is called multiple niche polymor- phism. Many herbivorous insects ha ...

THE GENETiCAl THEoRy of NATuRAl SElECTioN 125 Selection That favors the Most Common Balancing selection preserves genetic variat ...

126 CHAPTER 5 is shown in Figure 5.19C. The key feature is that if an allele’s frequency is below a threshold value, then select ...

THE GENETiCAl THEoRy of NATuRAl SElECTioN 127 The fundamental theorem of natural selection and the adaptive landscape Fisher sho ...

128 CHAPTER 5 an adaptive valley. If the allele frequency starts to the left of the low point, selection drives the allele frequ ...

THE GENETiCAl THEoRy of NATuRAl SElECTioN 129 into acorns.) As the mutation spreads, the mean fitness of individuals in the popu ...

130 CHAPTER 5 Deleterious Mutations Some mutations increase fitness: they make individuals more resistant to a dis- ease, say, o ...

THE GENETiCAl THEoRy of NATuRAl SElECTioN 131 with a hypothetical population without mutations. Mutations that reduce indi- vidu ...

■■Natural selection is any consistent difference in fitness among different phenotypes or geno- types. Evolution caused by natur ...

Several texts on population genetics give the cur- rent view of the field. John Gillespie’s Popula- tion Genetics: A Concise Gui ...

06_EVOL4E_CH06.indd 134 3/23/17 9:04 AM ...

What was the most important advance in human history? Fire? The wheel? The computer? A strong case can be made for the harnessin ...

136 CHAPTER 6 animals and plants to improve them for food production and other purposes. The chapter then describes how cor- rel ...

PHEnoTyPiC EvoluTion 137 the distribution of phenotypes in a population. The three rows show the situa- tion when different numb ...

138 CHAPTER 6 original population. This is because the new allele frequencies produce signifi- cant numbers of some genotypes th ...