This study draws on data from numerous sources that support the paradigm of natural hybridization as an important evolutionary process. The review of these data results in a challenge to the framework used by many evolutionary biologists, which sees the process of natural hybridization as maladaptive because it represents a violation of divergent evolution. In contrast, this book presents evidence of a significant role for natural hybridization in furthering adaptive evolution and evolutionary diversification in both plants and animals.
Author(s): Michael L. Arnold
Series: Oxford Series in Ecology and Evolution
Publisher: Oxford University Press
Year: 1997
Language: English
Pages: 232
Contents......Page 12
1.1 Natural hybridization: Definitions......Page 18
1.2 Natural hybridization: History of investigations......Page 20
1.3 Summary......Page 25
2.1 Introduction......Page 26
2.2 The Biological Species Concept......Page 28
2.3 The Recognition Species Concept......Page 31
2.4 The Cohesion Species Concept......Page 33
2.5 The Phylogenetic Species Concept......Page 34
2.6 Natural hybridization and species concepts: Illuminators or impediments?......Page 35
2.7 Summary......Page 36
3.1 Introduction......Page 38
3.2 Frequency and distribution of natural hybridization in plants......Page 39
3.2.1 The fossil record......Page 40
3.2.3 Heterogeneities......Page 41
3.2.4 Phylogenetic approach......Page 44
3.2.5 Phylogenetic approach and falsifying hybrid speciation hypotheses......Page 56
3.3 Frequency and distribution of natural hybridization in animals......Page 59
3.3.1 Bosmina fossil record......Page 60
3.3.2 Surveys of taxonomic groups......Page 62
3.3.3 Heterogeneities......Page 65
3.3.4 Phylogenetic approach......Page 67
3.4 Summary......Page 78
4.1 Introduction......Page 79
4.2 Premating barriers in plants......Page 81
4.3.1 The per locus......Page 84
4.3.2 Gamete recognition......Page 89
4.4 Post-insemination processes in animals......Page 93
4.4.2 Allonemobius......Page 94
4.4.3 Tribolium......Page 95
4.5 Post-pollination barriers in plants......Page 98
4.5.1 Haplopappus......Page 99
4.5.3 Annual species of Helianthus......Page 102
4.5.4 Iris fulva x I. hexagona......Page 105
4.5.5 Iris fulva x I. brevicaulis......Page 109
4.6 Self- and hetero-incompatibility......Page 113
4.6.1 Self-incompatibility: Introduction......Page 114
4.6.2 Self- and hetero-incompatibility in plants: Similarities and differences......Page 120
4.6.3 Postzygotic inviability and hybrid formation......Page 121
4.6.4 Hetero-incompatibility in animals and plants: common patterns and a model......Page 123
4.7 Summary......Page 126
5.1 Introduction......Page 128
5.2 Bounded Hybrid Superiority model......Page 131
5.3 Mosaic model......Page 133
5.4 Tension Zone model......Page 137
5.4.1 Expectations......Page 138
5.4.2 Case studies......Page 139
5.5 Fitness estimates of hybrids and their parents......Page 155
5.5.1 Chromosome races of Sceloporus grammicus......Page 158
5.5.3 Artemisia tridentata ssp. tridentata and A. t. ssp. vaseyana......Page 159
5.5.4 Iris fulva and I. brevicaulis......Page 160
5.6 A new conceptual framework: The "Evolutionary Novelty" model......Page 162
5.6.1 Rarity of F[sub(1)] formation, recency of contact, and the association of hybridization with ecotones and disturbance......Page 163
5.6.2 Formation of later generation hybrids......Page 165
5.6.3 Exogenous and endogenous selection and the structuring of hybrid zones......Page 166
5.7 Summary......Page 169
6.1 Introduction......Page 170
6.2.1 Homoploid speciation......Page 171
6.2.2 Polyploid speciation......Page 175
6.3.1 Natural hybridization, positive selection, and introgression......Page 177
6.3.2 Natural hybridization, introgression, and habitat invasion......Page 187
6.3.3 Natural hybridization and conservation biology......Page 190
6.4 Summary......Page 195
7.1 Viewpoint redefined......Page 197
7.2 Vision redefined......Page 198
References......Page 202
H......Page 228
Q......Page 229
X......Page 230
