25 80% chance 20% chance 80% chance 20% chance Figure 23.7Alleles in the populationFrequencies of allelesGametes producedp = frequency ofEach egg: Each sperm:CR allele = 0.8q = frequency of80%chance20%chance80%chance20%chanceCW allele = 0.2Figure 23.7 Selecting alleles at random from a gene pool.
48 Greater prairie chicken Figure 23.11Pre-bottleneck(Illinois, 1820)Post-bottleneck(Illinois, 1993)Greater prairie chickenRangeof greaterprairiechicken(a)Numberof allelesper locusPercentageof eggshatchedPopulationsizeLocationIllinois1930–1960s19931,000–25,000<505.23.793<50Figure Genetic drift and loss of genetic variation.Kansas, 1998(no bottleneck)750,0005.899Nebraska, 1998(no bottleneck)75,000–200,0005.896(b)
49 Greater prairie chicken Figure 23.11aPre-bottleneck(Illinois, 1820)Post-bottleneck(Illinois, 1993)Greater prairie chickenRangeof greaterprairiechickenFigure Genetic drift and loss of genetic variation.(a)
50 Number of alleles per locus Percentage of eggs hatched Population size Figure 23.11bNumberof allelesper locusPercentageof eggshatchedPopulationsizeLocationIllinois1930–1960s19931,000–25,000<505.23.793<50Kansas, 1998(no bottleneck)750,0005.899Figure Genetic drift and loss of genetic variation.Nebraska, 1998(no bottleneck)75,000–200,0005.896(b)
51 Greater prairie chicken Figure 23.11cGreater prairie chickenFigure Genetic drift and loss of genetic variation.
56 Population in which the surviving females eventually bred 60 Central Figure 23.12Population in which thesurviving femaleseventually bred60CentralpopulationCentral50NORTH SEAEasternpopulationEasternVlieland,the Netherlands402 kmSurvival rate (%)302010Figure Gene flow and local adaptation.Females bornin centralpopulationFemales bornin easternpopulationParus major
57 Figure 23.12aFigure Gene flow and local adaptation.Parus major
72 EXPERIMENT Recording of SC male’s call Recording of LC male’s call Figure 23.16aEXPERIMENTRecording of SCmale’s callRecording of LCmale’s callFemale graytree frogSC male graytree frogLC male graytree frogSC sperm Eggs LC spermFigure Inquiry: Do females select mates based on traits indicative of “good genes”?Offspring of Offspring ofSC father LC fatherSurvival and growth of these half-sibling offspring compared
73 Offspring Performance 1995 1996 Figure 23.16bRESULTSOffspring Performance19951996Larval survivalLC betterNSDLarval growthNSDLC betterTime to metamorphosisLC better(shorter)LC better(shorter)Figure Inquiry: Do females select mates based on traits indicative of “good genes”?NSD = no significant difference; LC better = offspring of LC males superior tooffspring of SC males.
83 Figure 23.UN01CRCRCWCWFigure 23.UN01 In-text figure, p. 473CRCW
84 Original population Evolved population Directional selection Figure 23.UN02OriginalpopulationEvolvedpopulationFigure 23.UN02 Summary figure, Concept 23.4DirectionalselectionDisruptiveselectionStabilizingselection
85 (1–8 represent pairs of sites) Figure 23.UN03Sampling sites(1–8 represent pairs of sites)12345678910112Allelefrequencieslap94 allelesOther lap allelesData from R. K. Koehn and T. J. Hilbish, The adaptive importance of genetic variation,American Scientist 75:134–141 (1987).Salinity increases toward the open ocean78564Figure 23.UN03 Test Your Understanding, question 83Long IslandSound21910AtlanticOcean11