Evolution, 4th Edition

PHEnoTyPiC EvoluTion 159 contribute, then the trait can evolve further before genetic variation is exhausted as alleles become f ...

160 CHAPTER 6 different animals independently evolve similar coloration, is that the result of changes at the same or at differe ...

■■An individual’s phenotype—the set of its visible traits—is determined by a combination of its genotype and environmental facto ...

SuGGESTionS FoR FuRTHER READinG There are two classic texts on quantitative genet- ics. Introduction to Quantitative Genetics by ...

in some cases, inheritance of a single allele, such as the sex-determining factor, will cause phenotypes to be so different tha ...

07_EVOL4E_CH07.indd 164 3/23/17 9:09 AM ...

Northern elephant seals are remarkable animals. They spend most of their lives at sea. While hunting fish and squid, the seals d ...

166 CHAPTER 7 with natural selection. The chapter then discusses how molecular differences among species accumulate in time. It ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 167 Each generation starts with N juveniles. This population size is fixed by the limited sp ...

168 CHAPTER 7 Figure 7.2 illustrates five fundamental features of drift. The first is that drift is unbiased: an allele frequenc ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 169 homozygous for one allele, roughly half would be fixed for the other allele. Within each ...

170 CHAPTER 7 College Station, Texas, and genotyped them at several loci [35]. FIGURE 7.4 shows the data from one locus. Allele ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 171 one copy to become the ancestor of all living copies will vary randomly between the simul ...

172 CHAPTER 7 only a single gene copy (or single individual) present then. There were nine other copies in that generation, and ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 173 ancestor is 2Ne generations. For Drosophila melanogaster, with an effective popula- tion ...

174 CHAPTER 7 populations now living far from southern Africa therefore experienced many founder events in their past, while tho ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 175 The explanation is that much of the polymorphism in DNA within species results from rando ...

176 CHAPTER 7 beneficial mutation eliminates variation in the surrounding region of chromosome (see Fig ure 5.15). In a similar ...

gENETIC dRIfT: EvolUTIoN AT RANdoM 177 size of about 7 million individuals in Australia. Analysis of their genetic variation sug ...

178 CHAPTER 7 vast majority of alleles fall into one of two categories. Some alleles are strongly selected (s >> 1/Ne), an ...