Natural hybridization as an evolutionary process

Annual Review of Ecology and Systematics

Volumn 23, Issue 1, 1992, Pages 237-261

  Arnold, Michael L ^a  

^a UNIVERSITY OF GEORGIA   (United States)

Author keywords

Adaptation; Hybrid speciation; Introgression; Natural selection

Indexed keywords

EVOLUTION; HYBRIDIZATION; NATURAL SELECTION; RETICULATE EVOLUTION;

EID: 0027019626     PISSN: 00664162     EISSN: None     Source Type: Journal    
DOI: 10.1146/annurev.es.23.110192.001321     Document Type: Article

References (182)

1. Anderson, E. 1948. Hybridization of the habitat. Evolution 2:1-9
2. Anderson, E. 1949. Introgressive Hybridization. New York: Wiley. 109 pp.
3. Anderson, E., Hubricht, L. 1938. Hybridization in Tradescantia. III. The evidence for introgressive hybridization. Am. J. Bot. 25:396-402
4. Anderson, E., Stebbins, G. L. Jr. 1954. Hybridization as an evolutionary stimulus. Evolution 8:378-88
5. Arnold, J., Asmussen, M. A., Avise, J. C. 1988. An epistatic mating system model can produce permanent cytonuclear disequilibria in a hybrid zone. Proc. Natl. Acad. Sci. USA 85:1893-96
6. Arnold, M. L., Bennett, B. D. 1992. Natural hybridization in Louisiana irises: genetic variation and ecological determinants. In Hybrid Zones and the Evolutionary Process, ed. R. G. Harrison. In press. Oxford: Oxford Univ. Press
7. Arnold, M. L., Bennett, B. D., Zimmer, E. A. 1990. Natural hybridization between Iris fulva and J. hexagona: pattern of ribosomal DNA variation. Evolution 44:1512-21
8. Arnold, M. L., Contreras, N., Shaw, D. D. 1988. Biased gene conversion and asymmetrical introgression between subspecies. Chromosoma 96:368-71
9. Arnold, M. L., Hamrick, J. L., Bennett, B. D. 1990. Allozyme variation in Louisiana irises: a test for introgression and hybrid speciation. Heredity 65:297-306
10. Arnold, M. L., Buckner, C. M., Robinson, J. J. 1991. Pollen mediated introgression and hybrid speciation in Louisiana irises. Proc. Natl. Acad. Sci. USA 88:1398-1402
11. Arnold, M. L., Robinson, J. J., Buckner, C. M., Bennett, B. D. 1992. Pollen dispersal and interspecific gene flow in Louisiana Irises. Heredity 68:399-404
12. Arnold, M. L., Shaw, D. D. 1985. The heterochromatin of grasshoppers from the Caledia captiva species complex. II. Cytological organisation of tandemly repeated DNA sequences. Chromosoma 93:183-90
13. Arnold, M. L., Shaw, D. D., Contreras, N. 1987. Ribosomal RNA-encoding DNA introgression across a narrow hybrid zone between two subspecies of grasshopper. Proc. Natl. Acad. Sci. USA 84:3946-50
14. Arnold, M. L., Wilkinson, P., Shaw, D. D., Marchant, A. D., Contreras, N. 1987. Highly repeated DNA and allozyme variation between sibling species: evidence for introgression. Genome 29:272-79
15. Asmussen, M. A., Arnold, J., Avise, J. C. 1987. Definition and properties of disequilibrium statistics for associations between nuclear and cytoplasmic genotypes. Genetics 115:755-68
16. Asmussen, M. A., Arnold, J., Avise, J. C. 1989. The effects of assortative mating and migration on cytonuclear associations in hybrid zones. Genetics 122:923-34
17. Asmussen, M. A., Schnabel, A. 1991. Comparative effects of pollen and seed migration on the cytonuclear structure of plant populations I. Maternal cytoplasmic inheritance. Genetics 128:639-54
18. Aubert, J., Solignac, M. 1990. Experimental evidence for mitochondrial DNA introgression between Drosophila species. Evolution 44:1272-82
19. Avise, J. C., Nelson, W. S., Arnold, J., Koehn, R. K., Williams, G. C., Thorsteinsson, V. 1990. The evolutionary genetic status of Icelandic eels. Evolution 44:1254-62
20. Avise, J. C., Saunders, N. C. 1984. Hybridization and introgression among species of sunfish (Lepomis): analysis by mitochondrial DNA and allozyme markers. Genetics 108: 237-55
21. Baker, M. C., Baker, A. E. M. 1990. Reproductive behavior of female buntings: isolating mechanisms in a hybridizing pair of species. Evolution 44:332-38
22. Baker, R. J. 1981. Chromosome flow between chromosomally characterized taxa of a volant mammal, Uroderma bilobatum (Chiroptera: Phyllostomatidae). Evolution 35:296-305
23. Baker, R. J., Davis, S. K., Bradley, R. D., Hamilton, M. J., Van Den Bussche, R. A. 1989. Ribosomal-DNA, mitochondrial-DNA, chromosomal, and allozymic studies on a contact zone in the pocket gopher, Geomys. Evolution 43:63-75
24. Barton, N. H. 1979. The dynamics of hybrid zones. Heredity 43:341-59
25. Barton, N. H., Hewitt, G. M. 1981. A chromosomal cline in the grasshopper Podisma pedestris. Evolution 35: 1008-1018
26. Barton, N. H., Hewitt, G. M. 1985. Analysis of hybrid zones. Annu. Rev. Ecol. Syst. 16:113-48
27. Bell, N. B., Lester, L. J. 1978. Genetic and morphological detection of introgression in a clinal population of Sabatia section Campestria (Gentianaceae). Syst. Bot. 3:87-104
28. Bennett, B. D. 1989. Habitat differentiation of Iris fulva Ker Gawler, Iris hexagona Walter, and their hybrids. PhD thesis. Louisiana State Univ. 117 pp.
29. Bennett, B. D., Grace, J. B. 1990. Shade tolerance and its effect on the segregation of two species of Louisiana Iris and their hybrids. Am. J. Bot. 77:100-7
30. Benson, L., Phillips, E. A., Wilder, P. A. et al. 1967. Evolutionary sorting of characters in a hybrid swarm. I: Direction of slope. Am. J. Bot. 54: 1017-26
31. Bert, T. M., Harrison, R. G. 1988. Hybridization in western Atlantic stone crabs (Genus Menippe): evolutionary history and ecological context influence species interactions. Evolution 42:528-44
32. Bigelow, R. S. 1965. Hybrid zones and reproductive isolation. Evolution 19:449-58
33. Birch, L. C., Vogt, W. G. 1970. Plasticity of taxonomic characters of the Queensland fruit flies Dacus tryoni and Dacus neohumeralis (Tephritidae). Evolution 24:320-43
34. Bradley, R. D., Davis, S. K., Baker, R. J. 1991. Genetic control of premating-isolating behavior: Kaneshiro's hypothesis and asymmetrical sexual selection in pocket gophers. J. Hered. 82:192-96
35. Briggs, B. G. 1962. Interspecific hybridization in the Ranunculus lappaceus group. Evolution 16:372-90
36. Brown, W. M., Wright, J. W. 1979. Mitochondrial DNA analyses and the origin and relative age of parthenogenetic lizards (genus Cnemidophorus). Science 203:1247-49
37. Butlin, R. 1989. Reinforcement of premating isolation. In Speciation and its Consequences, ed. D. Otte, J. A. Endler, pp. 158-79. Sunderland: Sinauer. 679 pp.
38. Carr, S. M., Ballinger, S. W., Deer, J. N., Blankenship, L. H., Bickham, J. W. 1986. Mitochondrial DNA analysis of hybridization between sympatric white-tailed deer and mule deer in west Texas. Proc. Natl. Acad. Sci. USA 83:9576-80
39. Carson, H. L., Clayton, F. E., Stalker, H. D. 1967. Karyotypic stability and speciation in Hawaiian Drosophila. Proc. Natl. Acad. Sci. USA 57:1280-85
40. Chandler, J. M., Jan, C. C., Beard, B. H. 1986. Chromosomal differentiation among the annual Helianthus species. Syst. Bot. 11:354-71
41. Daly, J. C., Wilkinson, P., Shaw, D. D. 1981. Reproductive isolation in relation to allozymic and chromosomal differentiation in the grasshopper Caledia captiva. Evolution 35:1164-79
42. DeMarais, B.D., Dowling, T. E., Douglas, M. E., Minckley, W. L., Marsh, P. C. 1992. Hybrid origin of Gila seminuda (Pisces: Cyprinidae): Implications for evolution and conservation. Proc. Natl. Acad. Sci. USA 89:2747-51
43. dePamphilis, C. W., Wyatt, R. 1989. Hybridization and introgression in Buckeyes (Aesculus: Hippocastanaceae): a review of the evidence and a hypothesis to explain long-distance gene flow. Syst. Bot. 14:593-611
44. Dobzhansky, Th. 1937. Genetics and the Origin of Species. New York: Columbia Univ. Press. 364 pp.
45. Dobzhansky, Th. 1953. Natural hybrids of two species of Arctostaphylos in the Yosemite region of California. Heredity 7:73-79
46. Dobzhansky, Th. 1970. Genetics of the Evolutionary Process. New York: Columbia Univ. Press. 505 pp.
47. Dowling, T. E., Brown, W. M. 1989. Allozymes, mitochondrial DNA, and levels of phylogenetic resolution among four minnow species (Notropis: Cyprinidae). Syst. Zool. 38:126-43
48. Dowling, T. E., Moore, W. S. 1985. Evidence for selection against hybrids in the family Cyprinidae (Genus Notropis). Evolution 39:152-58
49. Drake, D. W. 1981. Reproductive success of two Eucalyptus hybrid populations. I. generalized seed output model and comparison of fruit parameters. Aust. J. Bot. 29:25-35
50. Echelle, A. A., Connor, P. J. 1989. Rapid, geographically extensive genetic introgression after secondary contact between two pupfish species (Cyprinodon, Cyprinodontidae). Evolution 43:717-27
51. Endler, J. A. 1973. Gene flow and population differentiation. Science 179: 243-50
52. Endler, J. A. 1977. Geographic Variation, Special ion and Clines. Princeton, NJ: Princeton Univ. Press. 246 pp.
53. Ferns, S. D., Sage, R. D., Huang, C., Nielsen, J. T., Ritte, U., Wilson, A. C. 1983. Flow of mitochondrial DNA across a species boundary. Proc. Natl. Acad. Sci. USA 80:2290-94
54. Fisher, R. A. 1930. The Genetical Theory of Natural Selection. Oxford: Clarendon Press. 272 pp.
55. Fleischer, R. C., Rothstein, S. I. 1988. Known secondary contact and rapid gene flow among subspecies and dialects in the brown-headed cowbird. Evolution 42:1146-58
56. Gibbs, G. W. 1968. The frequency of interbreeding between two sibling species of Dacus (Diptera) in wild populations. Evolution 22:667-83
57. Gill, F. B., Murray, B. G. Jr. 1972. Discrimination behavior and hybridization of the blue-winged and golden-winged warblers. Evolution 26:282-93
58. Gillett, G. W. 1966. Hybridization and its taxonomic implications in the Scaevola gaudichaudiana complex of the Hawaiian islands. Evolution 20: 506-16
59. Goldman, M. A., LoVerde, P. T., Chrisman, C. L. 1983. Hybrid origin of polyploidy in freshwater snails of the genus Bulinus (Mollusca: Planorbidae). Evolution 37:592-600
60. Good, D. A. 1989. Hybridization and cryptic species in Dicamptodon (Caudata: Dicamptodontidae). Evolution 43:728-44
61. Gore, P. L., Potts, B. M., Volker, P. W., Megalos, J. 1990. Unilateral cross-incompatibility in Eucalyptus: the case of hybridisation between E. globulus and E. nitens. Aust. J. Bot. 38:383-94
62. Grant, V. 1963. The Origin of Adaptations. New York: Columbia Univ. Press. 606 pp.
63. Grant, V. 1981. Plant Speciation. New York: Columbia Univ. Press. 563 pp.
64. Grant, V., Grant, K. A. 1971. Dynamics of clonal microspecies in cholla cactus. Evolution 25:144-55
65. Griffin, A. R., Burgess, I. P., Wolf, L. 1988. Patterns of natural and manipulated hybridisation in the genus Eucalyptus L'Herit.-a review. Aust. J. Bot. 36:41-66
66. Haldane, J. B. S. 1948. The theory of a cline. J. Genet. 48:277-84
67. Hall, H. G. 1990. Parental analysis of introgressive hybridization between African and European honeybees using nuclear DNA RFLPs. Genetics 125: 611-21
68. Hardin, J. W. 1975. Hybridization and introgression in Quercus alba. J. Arnold Arb. 56:336-63
69. Harrison, R. G. 1983. Barriers to gene exchange between closely related cricket species. I. Laboratory hybridization studies. Evolution 37:245-51
70. Harrison, R. G. 1986. Pattern and process in a narrow hybrid zone. Heredity 56:337-49
71. Harrison, R. G. 1990. Hybrid zones: windows on evolutionary process. In Oxford Surveys in Evolutionary Biology, ed. D. Futuyma, J. Antonovics, 7:69-128. Oxford: Oxford Univ. Press.
72. Harrison, R. G., Rand, D. M., Wheeler, W. C. 1987. Mitochondrial DNA variation in field crickets across a narrow hybrid zone. Mol. Biol. Evol. 4:144-58
73. Heiser, C. B. 1973. Introgression reexamined. Bot. Rev. 39:347-66
74. Heiser, C. B. Jr., Smith, D.M., Clevenger, S. B., Martin, W. C. Jr. 1969. The North American Sunflowers (Helianthus). Mem. Torrey Bot. Club 22:1-218
75. Heywood, J. S. 1986. Clinal variation associated with edaphic ecotones in hybrid populations of Gaillardia pulchella. Evolution 40:1132-40
76. Honeycutt, R. L., Wilkinson, P. 1989. Electrophoretic variation in the parthenogenetic grasshopper Warramaba virgo and its sexual relatives. Evolution 43:1027-44
77. Howard, D. J. 1986. A zone of overlap and hybridization between two ground cricket species. Evolution 40:34-43
78. Hubbs, C. L. 1955. Hybridization between fish species in nature. Syst. Zool. 4:1-20
79. Key, K. H. L. 1968. The concept of stasipatric speciation. Syst. Zool. 17: 14-22
80. Key, K. H. L. 1981. Species, parapatry, and the morabine grasshoppers. Syst. Zool. 30:425-58
81. Kirkpatrick, J. B., Nunez, M. 1980. Vegetation-radiation relationships in mountainous terrain: eucalypt-dominated vegetation in the Risdon Hills, Tasmania. J. Biogeogr. 7:197-208
82. Kohlmann, B., Nix, H., Shaw, D. D. 1988. Environmental predictions and distributional limits of chromosomal taxa in the Australian grasshopper Caledia captiva (F.). Oecologia 75:483-93
83. Lamb,T., Avise, J. C. 1986. Directional introgression of mitochondrial DNA in a hybrid population of tree frogs: the influence of mating behavior. Proc. Natl. Acad. Sci. USA 83:2526-30
84. Lehman, N., Eisenhawer, A., Hansen, K., Mech, L. D., Peterson, R. O., et al. 1991. Introgression of Coyote mitochondrial DNA into sympatric North American gray wolf populations. Evolution 45:104-19
85. Lemeunier, F., Ashburner, M. 1984. Relationships within the melanogaster species subgroup of the genus Drosophila (Sophophora). IV. The chromosomes of two new species. Chromosoma 89:343-51
86. Lemeunier, F., David, J. R., Tsacas, L., Ashbumer, M. 1986. The melanogaster species group. In The Genetics and Biology of Drosophila, Vol 3, ed. M. Ashburner, H. L. Carson, J. N. Thompson, pp. 147-256. London: Academic Press
87. Levin, D. A. 1969. The challenge from a related species: a stimulus for saltational speciation. Am. Nat. 103:316-22
88. Levin, D. A., Bulinska-Radomska, Z. 1988. Effects of hybridization and inbreeding in Phlox. Am. J. Bot. 75: 1632-39
89. Lewontin, R. C. 1974. The Genetic Basis of Evolutionary Change. New York: Columbia Univ. Press. 346 pp.
90. Lewontin, R. C., Birch, L. C. 1966. Hybridization as a source of variation for adaptation to new environments. Evolution 20:315-36
91. Lotsy, J. P. 1916. Evolution by Means of Hybridization. The Hague: M. Nijhoff. 166 pp.
92. Mallet, J. 1986. Hybrid zones of Heliconius butterflies in Panama and the stability and movement of warning colour clines. Heredity 56: 191-202
93. Marchant, A. D. 1988. Apparent introgression of mitochondrial DNA across a narrow hybrid zone in the Caledia captiva species-complex. Heredity 60:39-46
94. Marchant, A. D., Arnold, M. L., Wilkinson, P. 1988. Gene flow across a chromosomal tension zone. I. Relicts of ancient hybridization. Heredity 61: 321-28
95. Matfield, B., Ellis, J. R. 1972. The allopolyploid origin and genomic constitution of Potentilla anglica. Heredity 29:315-27
96. Mayr, E. 1942. Systematics and the Origin of Species. New York: Columbia Univ. Press. 334 pp.
97. McArthur, E. D., Welch, B. L., Sanderson, S. C. 1988. Natural and artificial hybridization between big sagebrush (Artemisia tridentala) subspecies. J. Hered. 79:268-76
98. Mecham, J. S. 1960. Introgressive hybridization between two southeastern treefrogs. Evolution 14:445-57
99. Meyn, O., Emboden, W. A. 1987. Parameters and consequences of introgression in Salvia apiana x S. mellifera (Lamiaceae). Syst. Bot. 12:390-99
100. Montanucci, R. R. 1983. Natural hybridization between two species of collared lizards (Crotaphytus). Copeia 1983:1-11
101. Moore, W. S. 1977. An evaluation of narrow hybrid zones in vertebrates. Q. Rev. Biol. 52:263-77
102. Moore, W. S. 1987. Random mating in the northern flicker hybrid zone: implications for the evolution of bright and contrasting plumage patterns in birds. Evolution 41:539-46
103. Moore, W. S., Buchanan, D. B. 1985. Stability of the northern flicker hybrid zone in historical times: implications for adaptive speciation theory. Evolution 39:135-51
104. Moran, C. 1979. The structure of the hybrid zone in Caledia. Heredity 42:13-32
105. Moran, C., Shaw, D. D. 1977. Population cytogenetics of the genus Caledia (Orthoptera: Acridinae). III. Chromosomal polymorphism, racial parapatry and introgression. Chromosoma 63: 181-204
106. Moritz, C. 1983. Parthenogenesis in the endemic Australian lizard Heteronotia binoei (Gekkonidae). Science 220:735-37
107. Muller, C. H. 1952. Ecological control of hybridization in Quercus: a factor in the mechanism of evolution. Evolution 6:147-61
108. Nagle, J. J., Mettler, L. E. 1969. Relative fitness of introgressed and parental populations of Drosophila mojavensis and D. arizonensis. Evolution 23:519-24
109. Nason, J. D., Ellstrand, N. C., Arnold, M. L. 1992. Patterns of hybridization and introgression in populations of oaks, manzanitas, and irises. Am. J. Bot. 79:101-111
110. Nelson, K., Baker, R. J., Honeycutt, R. L. 1987. Mitochondrial DNA and protein differentiation between hybridizing cytotypes of the white-footed mouse, Peromyscus leucopus. Evolution 41:864-72
111. Nevo, E., Bar-El, H. 1976. Hybridization and speciation in fossorial mole rats. Evolution 30:831-40
112. Porter, A. H. 1990. Testing nominal species boundaries using gene flow statistics: the taxonomy of two hybridizing admiral butterflies (Limenitis: Nymphalidae). Syst. Zool. 39:131-47
113. Potts, B. M. 1986. Population dynamics and regeneration of a hybrid zone between Eucalyptus risdonii Hook. f. and E. amygdalina Labill. Aust. J. Bot. 34:305-29
114. Potts, B. M., Reid, J. B. 1983. Hybridization between Eucalyptus obliqua L'Herit. and E. pulchella Desf. Aust. J. Bot. 31:211-29
115. Potts, B. M., Reid, J. B. 1985. Variation in the Eucalyptus gunnii-archeri complex. II. The origin of variation. Aust. J. Bot. 33:519-41
116. Potts, B. M.,Reid, J. B. 1985. Analysis of a hybrid swarm between Eucalyptus risdonii Hook.f. and E. amygdalina Labill. Aust. J. Bot. 33:543-62
117. Potts, B. M., Reid, J. B. 1988. Hybridization as a dispersal mechanism. Evolution 42:1245-55
118. Potts, B. M., Reid, J. B. 1990. The evolutionary significance of hybridization in Eucalyptus. Evolution 44:2151-52
119. Powell, J. R. 1983. Interspecific cytoplasmic gene flow in the absence of nuclear gene flow: evidence from Drosophila. Proc. Natl. Acad. Sci. USA 80:492-95
120. Rand, D. M., Harrison, R. G. 1989. Ecological genetics of a mosaic hybrid zone: mitochondrial, nuclear, and reproductive differentiation of crickets by soil type. Evolution 43:432-49
121. Randolph, L. F. 1966. Iris nelsonii, a new species of Louisiana iris of hybrid origin. Baileya 14:143-69
122. Randolph, L. F., Nelson, I. S., Plaisted, R. L. 1967. Negative evidence of introgression affecting the stability of Louisiana Iris species. Cornell Univ. Agr. Expt. Stat. Memoir 398:1-56
123. Rattenbury, J. A. 1962. Cyclic hybridization as a survival mechanism in the New Zealand forest flora. Evolution 16:348-63
124. Rieseberg, L. H. 1991. Homoploid reticulate evolution in Helianthus (Asteraceae) evidence from ribosomal genes. Am. J. Bot. 78:1218-37
125. Rieseberg, L. H., Beckstrom-Sternberg, S. M., Liston, A., Arias, D. M. 1991. Phylogenetic and systematic inferences from chloroplast DNA and isozyme variation in Helianthus sect. Helianthus (Asteraceae). Syst. Bot. 16:50-76
126. Rieseberg, L. H., Beckstrom-Sternberg, S., Doan, K. 1990. Helianthus annuus ssp. texanus has chloroplast DNA and nuclear ribosomal RNA genes of Helianthus debilis ssp. cucumerifolius. Proc. Natl. Acad. Sci. USA 87:593-97
127. Rieseberg, L. H., Brunsfeld, S. 1992. Molecular evidence and plant introgression. In Plant Molecular Systematics, ed. D. E. Soltis, P. S. Soltis, J. J. Doyle, pp. 151-76. New York: Chapman & Hall
128. Rieseberg, L. H., Carter, R., Zona, S. 1990. Molecular tests of the hypothesized hybrid origin of two diploid Helianthus species (Asteraceae). Evolution 44:1498-1511
129. Rieseberg, L. H., Soltis, D. E. 1991. Phylogenetic consequences of cytoplasmic gene flow in plants. Evol. Trends Plants 5:65-84
130. Rieseberg, L. H., Soltis, D. E., Palmer, J. d. 1988. A molecular re-examination of introgression between Helianthus annuus and H. bolanderi (Compositae). Evolution 42:227-38
131. Rieseberg, L. H., Wendel, J. F. 1992. Introgression and its consequences in plants. In Hybrid Zones and the Evolutionary Process, ed. R. G. Harrison. Oxford: Oxford Univ. Press. In press
132. Riley, H. P. 1938. A character analysis of colonies of Iris fulva, Iris hexagona var. giganticaerulea and natural hybrids. Am. J. Bot. 25:727-38
133. Ritchie, M. G., Butlin, R. K., Hewitt, G. M. 1989. Assortative mating across a hybrid zone in Chorthippus parallelus (Orthoptera: Acrididae). J. Evol. Biol. 2:339-52
134. Ross, K. G., Vander Meer, R. K., Fletcher, D. J. C., Vargo, E. L. 1987. Biochemical phenotypic and genetic studies of two introduced fire ants and their hybrid (Hymenoptera: Formicidae). Evolution 41:280-93
135. Sage, R. D., Heyneraan, D., Lim, K-C., Wilson, A. C. 1986. Wormy mice in a hybrid zone. Nature 324:60-63
136. Sage, R. D., Selander, R. K. 1979. Hybridization between species of the Rana pipiens complex in central Texas. Evolution 33:1069-88
137. Sanderson, N. 1989. Can gene flow prevent reinforcement? Evolution 43: 1223-35
138. Sattler, P. W. 1985. Introgressive hybridization between the Spadefoot toads Scaphiopus bombifrons and 5. multiplicatus (Salientia: Pelobatidae). Copeia 1985:324-32
139. Schemske, D. W., Morgan, M. T. 1990. The evolutionary significance of hybridization in Eucalyptus. Evolution 44: 2150-51
140. Schnabel, A., Asmussen, M. A. 1989. Definition and properties of disequilibria within nuclear-mitochondrial-chloroplast and other nuclear-dicytoplasmic systems. Genetics 123:199-215
141. Shaw, D. D. 1976. Population cytogenetics of the genus Caledia (Orthoptera: Acridinae). I. Inter-and intra- specific karyotype diversity. Chromosoma 54:221-43
142. Shaw, D. D. 1981. Chromosomal hybrid zones in orthopteroid insects. In Evolution and Speciation: Essays in Honour of M. J. D. White, ed. W. R. Atchley, D. S. Woodruff, pp. 146-70. Cambridge: Cambridge Univ. Press
143. Shaw, D. D., Coates, D. J., Arnold, M. L. 1988. Complex patterns of chromosomal variation along a latitudinal cline in the grasshopper Caledia captiva. Genome 30:108-17
144. Shaw, D. D., Coates, D. J., Arnold, M. L., Wilkinson, P. 1985. Temporal variation in the chromosomal structure of a hybrid zone and its relationship to karyotypic repatterning. Heredity 55: 293-306
145. Shaw, D. D., Marchant, A. D., Arnold, M. L., Contreras, N. 1988. Chromosomal rearrangements, ribosomal genes and mitochondrial DNA: introgression across a narrow hybrid zone. In Kew Chromosome Conference III, ed. P. E. Brandham, M. D. Bennett, pp. 121-129. London: Allen & Unwin
146. Shaw, D. D., Marchant, A. D., Arnold, M. L., Contreras, N., Kohlmann, B. 1990. The control of gene flow across a narrow hybrid zone: a selective role for chromosomal rearrangement? Can. J. Zool. 68:1761-69
147. Shaw, D. D., Moran, C., Wilkinson, P. 1980. Chromosomal reorganisation, geographic differentiation and the mechanism of speciation in the genus Caledia. In Insect Cytogenetics, ed. R. L. Blackman, G. M. Hewitt, and M. Ashburner, pp. 171-94. Oxford: Blackwell Scientific
148. Shaw, D. D., Webb, G. C., Wilkinson, P. 1976. Population cytogenetics of the genus Caledia (Orthoptera: Acridinae). II. Variation in the pattern of C-banding. Chromosoma 56:169-90
149. Shaw, D. D., Wilkinson, P. 1980. Chromosome differentiation, hybrid breakdown and the maintenance of a narrow hybrid zone in Caledia. Chromosoma 80:1-31
150. Sibley, C. G. 1954. Hybridization in the red-eyed towhees of Mexico. Evolution 8:252-90
151. Slatkin, M. 1987. Gene flow and the geographic structure of natural populations. Science 236:787-92
152. Smith-Huerta, N. L. 1986. Isozymic diversity in three allotetraploid Clarkia species and their putative diploid progenitors. J. Hered. 77:349-54
153. Smyth, C. A., Hamrick, J. L. 1987. Realized gene flow via pollen in artificial populations of Musk Thistle, Carduus nutans L. Evolution 41:613-19
154. Solignac, M., Monnerot, M. 1986. Race formation, speciation, and introgression within Drosophila simulons, D. mauritiana, and D. sechellia inferred from mitochondrial DNA analysis. Evolution 40:531-39
155. Spolsky, C., Uzzell, T. 1984. Natural interspecies transfer of mitochondrial DNA in amphibians. Proc. Natl. Acad. Sci. USA 81:5802-5
156. Stangl, F. B. Jr. 1986. Aspects of a contact zone between two chromosomal races of Peromyscus leucopus (Rodentia: Cricetidae). J. Mamm. 67: 465-73
157. Stebbins, G. L. 1959. The role of hybridization in evolution. Am. Philos. Soc. 103:231-51
158. Szymura, J. M., Barton, N. H. 1986. Genetic analysis of a hybrid zone between the fire-bellied toads, Bombina bombina and B. variegata, near Cracow in southern Poland. Evolution 40:1141-59
159. Tegelstrom, H., Gelter, H. P. 1990. Haldane's rule and sex biased gene flow between two hybridizing flycatcher species (Ficedula albicollis and F. hypoleuca, Aves: Muscicapidae). Evolution 44:2012-21
160. Thompson, J. D. 1991. The biology of an invasive plant. BioScience 41: 393-401
161. Vanlerberghe, F., Dod, B., Boursot, P., Bellis, M., Bonhomme, F. 1986. Absence of Y-chromosome introgression across the hybrid zone between Mus musculus domesticus and Mus musculus. Genet. Res. 48:191-97
162. Viosca, P. Jr. 1935. The irises of southeastern Louisiana: a taxonomic and ecological interpretation. J. Am. Iris Soc. 57:3-56
163. Vrijenhoek, R. C., Angus, R. A., Schultz, R. J. 1977. Variation and heterozygosity in sexually vs. clonally reproducing populations of Poeciliopsis. Evolution 31:767-81
164. Wagner, D. B., Furnier, G. R., SaghaiMaroof, M. A., Williams, S. M., Dancik, B. P., Allard, R. W. 1987. Chloroplast DNA polymorphisms in lodgepole and jack pines and their hybrids. Proc. Natl. Acad. Sci. USA 4:2097-100
165. Wagner, W. H. Jr. 1969. The role and taxonomic treatment of hybrids. BioScience 19:785-789
166. Wagner, W. H. Jr. 1970. Biosystematics and evolutionary noise. Taxon 19:146-51
167. Wagner, W. H. Jr., Schoen, D. J. 1976. Shingle oak (Quercus imbricaria) and its hybrids in Michigan. Mich. Bot. 15:141-55
168. Warwick, S. I., Bain, J. F., Wheatcroft, R., Thompson, B. K. 1989. Hybridization and introgression in Carduus nutans and C. acanthoides reexamined. Syst. Bot. 14:476-94
169. Wasserman, A. O. 1957. Factors affecting interbreeding in sympatric species of spadefoots (Genus Scaphiopus). Evolution 11:320-38
170. Wendel, J. F. 1989. New World tetraploid cottons contain Old World cytoplasm. Proc. Natl. Acad. Sci. USA 86:4132-36
171. White, M. J. D. 1978. Modes of Speciation. San Francisco: Freeman. 455
172. Whitham, T. G. 1989. Plant hybrid zones as sinks for pests. Science 244: 1490-93
173. Whittemore, A. T., Schaal, B. A. 1991. Interspecific gene flow in sympatric oaks. Proc. Natl. Acad. Sci. USA 88: 2540-44
174. Wiegand, K. M. 1935. A taxonomist's experience with hybrids in the wild. Science 81:161-66
175. Williams, E. G., Rouse, J. L. 1988. Disparate style lengths contribute to isolation of species in Rhododendron. Aust. J. Bot. 36:183-91
176. Woodruff, D. S. 1973. Natural hybridization and hybrid zones. Syst. Zool. 22:213-18
177. Woodruff, D. S., Gould, S. J. 1987. Fifty years of interspecific hybridization: genetics and morphometrics of a controlled experiment on the land snail Cerion in the Florida keys. Evolution 41:1022-45
178. Wright, S. 1931. Evolution in mendelian populations. Genetics 16:97-159
179. Wright, S. 1969. Evolution and the Genetics of Populations, Vol. 2, The Theory of Gene Frequencies. Chicago: Univ. Chicago Press. 511 pp.
180. Wynn, A. H. 1986. Linkage disequilibrium and a contact zone in Plethodon cinereus on the del-mar-va peninsula. Evolution 40:44-54
181. Yang, S. Y., Selander, R. K. 1968. Hybridization in the grackle Quiscalus quiscula in Louisiana. Syst. Zool. 17: 107-44
182. Zohary, D., Feldman, M. 1962. Hybridization between amphidiploids and the evolution of polyploids in the wheat (Aegilops-Triticum) group. Evolution 16:44-61