Evolution, 4th Edition

SPECiES And SPECiATion 219 Futuyma Kirkpatrick Evolution, 4e Sinauer Associates Troutt Visual Services Evolution4e_0906.ai Date ...

220 CHAPTER 9 Reproductive isolation Gene flow between biological species is prevented by biological differences called reproduc ...

SPECiES And SPECiATion 221 elevation, pollinator fidelity alone is 98 percent effective. If a flower receives both species’ poll ...

different species, partly during the process of speciation, and partly after the repro- ductive barriers evolved. Because geneti ...

SPECiES And SPECiATion 223 Gametic isolation occurs when gametes of different species fail to unite. This barrier is important i ...

224 CHAPTER 9 Postzygotic isolation is intrinsic if hybrids suffer high mortality, or are partially or entirely sterile, irrespe ...

SPECiES And SPECiATion 225 rearrangements are inversions and reciprocal translocations (see p. 90). Especially in the case of tr ...

450-plus species of cichlid fishes evolved from 5 ancestral species in Lake Victoria in just 15,000 years (see opening of this c ...

SPECiES And SPECiATion 227 postzygotic isolation probably plays a minor role in speciation. It may, however, affect the further ...

228 CHAPTER 9 Can different regimes of natural selection cause popula- tions of a species to become different species? Darwin an ...

SPECiES And SPECiATion 229 fertility. Selection therefore favors mutations at other loci that restore full fertility by disablin ...

230 CHAPTER 9 advantageous because fertilization by more than one sperm kills the egg. Any such changes in the egg will impose s ...

SPECiES And SPECiATion 231 offspring that are more likely to pass on her genes [12].) This is one reason why the distinction bet ...

232 CHAPTER 9 Data from Drosophila show exactly the expected pattern. In FIGURE 9.18, the strength of prezygotic isolation betwe ...

SPECiES And SPECiATion 233 tetraploid taxa do indeed reproduce by selfing or vegetative propagation, and most differ from their ...

234 CHAPTER 9 between two parental species, Helianthus annuus and H. petiolaris (see Fig ure 2.11) [81]. All have the same numbe ...

SPECiES And SPECiATion 235 several generations later [31, 54]. Typically a few of the replicate populations dis- play sexual iso ...

236 CHAPTER 9 gametes, not by geographic distance. In species that disperse little or are faithful to one habitat, populations m ...

SPECiES And SPECiATion 237 that occupy different river systems (see Figure 9.15B). Often, allopatric speciation can be related t ...

238 CHAPTER 9 [4]. A second outcome is that a hybrid zone is formed (for example, between the toads in Figure 9.4). Allele frequ ...