A rapid method of speciation that has been important in the history of flowering plants is

1. Jordan DS. 1905. The origin of species through isolation. Science 22, 545–562 (doi:10.1126/science.22.566.545) [PubMed] [Google Scholar]

2. Jordan DS. 1908. The law of geminate species. Am. Nat. 42, 73–80 (doi:10.1086/278905) [Google Scholar]

3. Mayr E. 1959. Isolation as an evolutionary factor. Proc. Am. Philos. Soc. 103, 221–230 [Google Scholar]

4. Anderson S, Evensen MK. 1978. Randomness in allopatric speciation. Syst. Biol. 27, 421–430 (doi:10.1093/sysbio/27.4.421) [Google Scholar]

5. Fitzpatrick BM, Turelli M. 2006. The geography of mammalian speciation: mixed signals from phylogenies and range maps. Evolution 60, 601–615 [PubMed] [Google Scholar]

6. Futuyma DJ. 1986. Evolutionary biology. Sunderland, MA: Sinauer Associates [Google Scholar]

7. Coyne JA, Orr HA. 2004. Speciation. Sunderland, MA: Sinauer Associates [Google Scholar]

8. Berlocher SH, Feder JL. 2002. Sympatric speciation in phytophagous insects: moving beyond controversy? Annu. Rev. Entomol. 47, 773–815 (doi:10.1146/annurev.ento.47.091201.145312) [PubMed] [Google Scholar]

9. Rundle HD, Nosil P. 2005. Ecological speciation. Ecol. Lett. 8, 336–352 (doi:10.1111/j.1461-0248.2004.00715.x) [Google Scholar]

10. Nosil P. 2008. Speciation with gene flow could be common. Mol. Ecol. 17, 2103–2106 (doi:10.1111/j.1365-294X.2008.03715.x) [PubMed] [Google Scholar]

11. Darwin C. 1859. The origin of species. London, UK: John Murray [Google Scholar]

12. Wiens JJ, et al. 2010. Niche conservatism as an emerging principle in ecology and conservation biology. Ecol. Lett. 13, 1310–1324 (doi:10.1111/j.1461-0248.2010.01515.x) [PubMed] [Google Scholar]

13. Burns JH, Strauss SY. 2011. More closely related species are more ecologically similar in an experimental test. Proc. Natl Acad. Sci. USA 108, 5302–5307 (doi:10.1073/pnas.1013003108) [PMC free article] [PubMed] [Google Scholar]

14. Barraclough TG, Vogler AP. 2000. Detecting the geographical pattern of speciation from species-level phylogenies. Am. Nat. 155, 419–434 (doi:10.1086/303332) [PubMed] [Google Scholar]

15. Losos JB, Glor RE. 2003. Phylogenetic comparative methods and the geography of speciation. Trends Ecol. Evol. 18, 220–227 (doi:10.1016/S0169-5347(03)00037-5) [Google Scholar]

16. Nattier R, Grandcolas P, Elias M, Desutter-Grandcolas L, Jourdan H, Couloux A, Robillard T. 2012. Secondary sympatry caused by range expansion informs on the dynamics of microendemism in a biodiversity hotspot. PLoS ONE 7, e48047 (doi:10.1371/journal.pone.0048047) [PMC free article] [PubMed] [Google Scholar]

17. Dayan T, Simberloff D. 2005. Ecological and community-wide character displacement: the next generation. Ecol. Lett. 8, 875–894 (doi:10.1111/j.1461-0248.2005.00791.x) [Google Scholar]

18. Davies TJ, Meiri S, Barraclough TG, Gittleman JL. 2007. Species co-existence and character divergence across carnivores. Ecol. Lett. 10, 146–152 (doi:10.1111/j.1461-0248.2006.01005.x) [PubMed] [Google Scholar]

19. Crawford DJ. 2010. Progenitor-derivative species pairs and plant speciation. Taxon 59, 1413–1423 [Google Scholar]

20. Gottlieb LD. 2004. Rethinking classic examples of recent speciation in plants. New Phytol. 161, 71–82 (doi:10.1046/j.1469-8137.2003.00922.x) [Google Scholar]

21. Mayr E. 1954. Change of genetic environment and evolution. In Evolution as a process (eds Huxley J, Hardy A, Ford E.), pp. 157–180 London, UK: Allen and Unwin [Google Scholar]

22. Grant V. 1981. Plant speciation. New York, NY: Columbia University Press [Google Scholar]

23. Lewis H, Roberts MR. 1956. The origin of Clarkia lingulata. Evolution 10, 126–138 (doi:10.2307/2405888) [Google Scholar]

24. Lewis H. 1962. Catastrophic selection as a factor in speciation. Evolution 16, 257–271 (doi:10.2307/2406275) [Google Scholar]

25. Raven PH, Axelrod DI. 1978. Origin and relationships of the California flora. Berkeley, CA: University of California Press [Google Scholar]

26. Brown JWL. 1957. Centrifugal speciation. Q. Rev. Biol. 32, 247–277 (doi:10.1086/401875) [Google Scholar]

27. Lande R. 1982. Rapid origin of sexual isolation and character divergence in a cline. Evolution 36, 213–223 (doi:10.2307/2408039) [PubMed] [Google Scholar]

28. Kawecki TJ. 1997. Sympatric speciation via habitat specialization driven by deleterious mutations. Evolution 51, 1751–1763 (doi:10.2307/2410998) [PubMed] [Google Scholar]

29. Dieckmann U, Doebeli M. 1999. On the origin of species by sympatric speciation. Nature 400, 354–357 (doi:10.1038/22521) [PubMed] [Google Scholar]

30. Fitzpatrick BM, Fordyce JA, Gavrilets S. 2008. What, if anything, is sympatric speciation? J. Evol. Biol. 21, 1452–1459 (doi:10.1111/j.1420-9101.2008.01611.x) [PubMed] [Google Scholar]

31. Dobzhansky T. 1940. Speciation as a stage in evolutionary divergence. Am. Nat. 74, 312–321 (doi:10.1086/280899) [Google Scholar]

32. Grossenbacher DL, Whittall JB. 2011. Increased floral divergence in sympatric monkeyflowers. Evolution 65, 2712–2718 (doi:10.1111/j.1558-5646.2011.01306.x) [PubMed] [Google Scholar]

33. Baker HG. 1959. Reproductive methods as factors in speciation in flowering plants. Cold Spring Harb. Symp. Quant. Biol. 24, 177–191 (doi:10.1101/SQB.1959.024.01.019) [PubMed] [Google Scholar]

34. Ramsey J, Schemske DW. 1998. Pathways, mechanisms, and rates of polyploid formation in flowering plants. Annu. Rev. Ecol. Syst. 29, 467–501 (doi:10.1146/annurev.ecolsys.29.1.467) [Google Scholar]

35. Wood TE, Takebayashi N, Barker MS, Mayrose I, Greenspoon PB, Rieseberg LH. 2009. The frequency of polyploid speciation in vascular plants. Proc. Natl Acad. Sci. USA 106, 13 875–13 879 (doi:10.1073/pnas.0812917106) [PMC free article] [PubMed] [Google Scholar]

36. Rieseberg LH, Brouillet L. 1994. Are many plant species paraphyletic? Taxon 43, 21–32 (doi:10.2307/1223457) [Google Scholar]

37. Antonovics J. 1968. Evolution in closely adjacent plant populations. V. Evolution of self-fertility. Heredity 23, 219–238 (doi:10.1038/hdy.1968.30) [Google Scholar]

38. Otto SP, Whitton J. 2000. Polyploid incidence and evolution. Annu. Rev. Genet. 34, 401–437 (doi:10.1146/annurev.genet.34.1.401) [PubMed] [Google Scholar]

39. Abbott RJ, Lowe AJ. 2004. Origins, establishment and evolution of new polyploid species: Senecio cambrensis and S. eboracensis in the British Isles. Biol. J. Linn. Soc. 82, 467–474 (doi:10.1111/j.1095-8312.2004.00333.x) [Google Scholar]

40. Soltis DE, Soltis PS, Tate JA. 2004. Advances in the study of polyploidy since plant speciation. New Phytol. 161, 173–191 (doi:10.1046/j.1469-8137.2003.00948.x) [Google Scholar]

41. Baldwin BG. 2005. Origin of the serpentine-endemic herb Layia discoidea from the widespread L. glandulosa (Compositae). Evolution 59, 2473–2479 [PubMed] [Google Scholar]

42. Runquist RB, Stanton ML. 2013. Asymmetric and frequency-dependent pollinator-mediated interactions may influence competitive displacement in two vernal pool plants. Ecol. Lett. 16, 183–190 (doi:10.1111/ele.12026) [PubMed] [Google Scholar]

43. Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403, 853–858 (doi:10.1038/35002501) [PubMed] [Google Scholar]

44. California Native Plant Society 2001. Inventory of rare and endangered plants of California, 6th edn Sacramento, CA: CNPS [Google Scholar]

45. Thorne J, Viers J, Price J, Stoms D. 2009. Spatial patterns of endemic plants in California. Nat. Areas J. 29, 344–366 (doi:10.3375/043.029.0402) [Google Scholar]

46. Kruckeberg AR. 1991. An essay: geoedaphics and island biogeography for vascular plants. Aliso 13, 225–238 [Google Scholar]

47. Anacker BL, Whittall JB, Goldberb EE, Harrison SP. 2011. Origins and consequences of serpentine endemism in the California flora. Evolution 63, 365–376 (doi:10.1111/j.1558-5646.2010.01114.x) [PubMed] [Google Scholar]

48. Kay KM, Ward KL, Watt LR, Schemske DW. 2011. Plant speciation. In Serpentine: the evolution and ecology of a model system (eds Harrison SP, Rajakaruna N.), pp. 71–96 Berkeley, CA: University of California Press [Google Scholar]

49. Lancaster LT, Kay KM. 2013. Origin and diversification of the California flora: re-examining classic hypotheses with molecular phylogenies. Evolution 67, 1041–1054 (doi:10.1111/evo.12016) [PubMed] [Google Scholar]

50. Stebbins GL, Major J. 1965. Endemism and speciation in the California flora. Ecol. Monogr. 35, 1–35 (doi:10.2307/1942216) [Google Scholar]

51. Harrison SP. 2013. Plant and animal endemism in the California Floristic Province. Berkeley, CA: University of California Press [Google Scholar]

52. Nakazato T, Warren DL, Moyle LC. 2010. Ecological and geographic modes of species divergence in wild tomatoes. Am. J. Bot. 97, 680–693 (doi:10.3732/ajb.0900216) [PubMed] [Google Scholar]

53. Webb CO, Donoghue MJ. 2005. Phylomatic: tree assembly for applied phylogenetics. Mol. Ecol. Notes 5, 181–183 (doi:10.1111/j.1471-8286.2004.00829.x) [Google Scholar]

54. Stamatakis A, Hoover P, Rougemont J. 2008. A rapid bootstrap algorithm for the RAxML web servers. Syst. Biol. 57, 758–771 (doi:10.1080/10635150802429642) [PubMed] [Google Scholar]

55. Edgar RC. 2004. MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Res. 32, 1792–1797 (doi:10.1093/nar/gkh340) [PMC free article] [PubMed] [Google Scholar]

56. Paradis E. 2013. Molecular dating of phylogenies by likelihood methods: a comparison of models and a new information criterion. Mol. Phylogenet. Evol. 67, 436–444 (doi:10.1016/j.ympev.2013.02.008) [PubMed] [Google Scholar]

57. Blomberg SP, Garland T, Jr, Ives AR. 2003. Testing for phylogenetic signal in comparative data: behavioral traits are more labile. Evolution 57, 717–745 [PubMed] [Google Scholar]

58. Baldwin BC, Goldman D, Keil D, Patterson R, Rosatti T, Wilken D. 2012. The Jepson manual: vascular plants of California, 2nd edn Berkeley, CA: University of California Press [Google Scholar]

59. Warren DL, Glor RE, Turelli M. 2008. Environmental niche equivalency versus conservatism: quantitative approaches to niche evolution. Evolution 62, 2868–2883 (doi:10.1111/j.1558-5646.2008.00482.x) [PubMed] [Google Scholar]

60. Benjamini Y, Hochberg Y. 1995. Controlling the false discovery rate: a practical and powerful approach to multiple testing. J. R. Stat. Soc. Ser. B Methodol. 57, 289–300 [Google Scholar]

61. Goodwillie C. 1999. Multiple origins of self-compatibility in Linanthus section Leptosiphon (Polemoniaceae): phylogenetic evidence from internal-transcribed-spacer sequence data. Evolution 53, 1387–1395 (doi:10.2307/2640885) [PubMed] [Google Scholar]

62. Grossenbacher DL, Veloz SD, Sexton JP. In press Niche and range size patterns suggest that speciation begins in small, ecologically diverged populations in North American monkeyflowers (Mimulus spp.). Evolution. [PubMed] [Google Scholar]

63. Shaw KL. 2002. Conflict between nuclear and mitochondrial DNA phylogenies of a recent species radiation: what mtDNA reveals and conceals about modes of speciation in Hawaiian crickets. Proc. Natl Acad. Sci. USA 99, 16 122–16 127 (doi:10.1073/pnas.242585899) [PMC free article] [PubMed] [Google Scholar]

64. Johnson NK, Cicero C. 2002. The role of ecologic diversification in sibling speciation of Empidonax flycatchers (Tyrannidae): multigene evidence from mtDNA. Mol. Ecol. 11, 2065–2081 (doi:10.1046/j.1365-294X.2002.01588.x) [PubMed] [Google Scholar]

65. Turelli M, Lipkowitz JR, Brandvain Y. In press On the Coyne and Orr-igin of species: effects of intrinsic postzygotic isolation, ecological differentiation, X chromosome size, and sympatry on Drosophila speciation. Evolution (doi:10.1111/evo.12330) [PMC free article] [PubMed] [Google Scholar]

66. Ackerly DD. 2003. Community assembly, niche conservatism, and adaptive evolution in changing environments. Int. J. Plant Sci. 164, 165–184 (doi:10.1086/368401) [Google Scholar]

67. Peterson AT. 2011. Ecological niche conservatism: a time-structured review of evidence. J. Biogeogr. 38, 817–827 (doi:10.1111/j.1365-2699.2010.02456.x) [Google Scholar]

68. Webb CO, Ackerly DD, McPeek MA, Donoghue MJ. 2002. Phylogenies and community ecology. Annu. Rev. Ecol. Syst. 33, 475–505 (doi:10.1146/annurev.ecolsys.33.010802.150448) [Google Scholar]

69. Sargent RD, Ackerly DD. 2008. Plant–pollinator interactions and the assembly of plant communities. Trends Ecol. Evol. 23, 123–130 (doi:10.1016/j.tree.2007.11.003) [PubMed] [Google Scholar]

70. Yost JM, Barry T, Kay KM, Rajakaruna N. 2012. Edaphic adaptation maintains the coexistence of two cryptic species on serpentine soils. Am. J. Bot. 99, 890–897 (doi:10.3732/ajb.1100521) [PubMed] [Google Scholar]

71. Cadena CD, et al. 2012. Latitude, elevational climatic zonation and speciation in New World vertebrates. Proc. R. Soc. B 279, 194–201 (doi:10.1098/rspb.2011.0720) [PMC free article] [PubMed] [Google Scholar]

72. Clausen J, Keck D, Hiesey WM. 1948. Experimental studies on the nature of species. III. Environmental responses of climatic races of Achillea. Washington, DC: Carnegie Institution of Washington [Google Scholar]

73. Smith HM. 1965. More evolutionary terms. Syst. Biol. 14, 57–58 [Google Scholar]

74. van der Niet T, Johnson SD. 2009. Patterns of plant speciation in the Cape floristic region. Mol. Phylogenet. Evol. 51, 85–93 (doi:10.1016/j.ympev.2008.11.027) [PubMed] [Google Scholar]

75. Cowling RM, Rundel PW, Lamont BB, Kalin Arroyo M, Arianoutsou M. 1996. Plant diversity in Mediterranean-climate regions. Trends Ecol. Evol. 11, 362–366 (doi:10.1016/0169-5347(96)10044-6) [PubMed] [Google Scholar]

76. Goldblatt P, Manning JC. 2002. Plant diversity of the Cape region of southern Africa. Ann. Mo. Bot. Gard. 89, 281–302 (doi:10.2307/3298566) [Google Scholar]

77. Martin NH, Willis JH. 2007. Ecological divergence associated with mating system causes nearly complete reproductive isolation between sympatric Mimulus species. Evolution 61, 68–82 (doi:10.1111/j.1558-5646.2007.00006.x) [PubMed] [Google Scholar]

78. Fishman L, Willis JH. 2001. Evidence for Dobzhansky–Muller incompatiblities contributing to the sterility of hybrids between Mimulus guttatus and M. nasutus. Evolution 55, 1932–1942 [PubMed] [Google Scholar]

79. Fishman L, Willis JH. 2006. A cytonuclear incompatibility causes anther sterility in Mimulus hybrids. Evolution 60, 1372–1381 [PubMed] [Google Scholar]

80. Grant PR, Grant BR. 2007. How and why species multiply: the radiation of Darwin‘s finches. Princeton, NJ: Princeton University Press [Google Scholar]

81. Lewis H. 1961. Experimental sympatric populations of Clarkia. Am. Nat. 95, 155–168 (doi:10.1086/282173) [Google Scholar]

82. Gottlieb LD. 1974. Genetic confirmation of the origin of Clarkia lingulata. Evolution 28, 244–250 (doi:10.2307/2407325) [PubMed] [Google Scholar]

83. Sytsma KJ, Gottlieb LD. 1986. Chloroplast DNA evolution and phylogenetic relationships in Clarkia sect. Peripetasma (Onagraceae). Evolution 40, 1248–1261 (doi:10.2307/2408951) [PubMed] [Google Scholar]

84. Ford VS, Gottlieb LD. 2003. Reassessment of phylogenetic relationships in Clarkia sect. Sympherica. Am. J. Bot. 90, 284–292 (doi:10.3732/ajb.90.2.284) [PubMed] [Google Scholar]

85. Chesson P. 2000. Mechanisms of maintenance of species diversity. Annu. Rev. Ecol. Syst. 31, 343–366 (doi:10.1146/annurev.ecolsys.31.1.343) [Google Scholar]

86. Adler PB, HilleRisLambers J, Levine JM. 2007. A niche for neutrality. Ecol. Lett. 10, 95–104 (doi:10.1111/j.1461-0248.2006.00996.x) [PubMed] [Google Scholar]

87. Ackerly DD. 2000. Taxon sampling, correlated evolution, and independent contrasts. Evolution 54, 1480–1492 [PubMed] [Google Scholar]

88. Swenson NG, Enquist BJ, Pither J, Thompson J, Zimmerman JK. 2006. The problem and promise of scale dependency in community phylogenetics. Ecology 87, 2418–2424 (doi:10.1890/0012-9658(2006)87[2418:TPAPOS]2.0.CO;2) [PubMed] [Google Scholar]

89. Ricklefs RE. 1987. Community diversity: relative roles of local and regional processes. Science 235, 167–171 (doi:10.1126/science.235.4785.167) [PubMed] [Google Scholar]

90. Cahill JF, Kembel SW, Lamb EG, Keddy PA. 2008. Does phylogenetic relatedness influence the strength of competition among vascular plants? Perspect. Plant Ecol. Evol. Syst. 10, 41–50 (doi:10.1016/j.ppees.2007.10.001) [Google Scholar]

91. Donoghue MJ. 2008. A phylogenetic perspective on the distribution of plant diversity. Proc. Natl Acad. Sci. USA 105, 11 549–11 555 (doi:10.1073/pnas.0801962105) [PMC free article] [PubMed] [Google Scholar]

Page 2

Geographical and niche attributes among sister–sister pairs and sister–non-sister congener pairs. (Ecological and reproductive shifts were scored as 0 for ‘no shift’, 0.5 for ‘partial shift’ and 1.0 for ‘shift present’. Morphological trait contrasts were calculated as |log(XA) − log(XB)|, where X is the trait value of species A and B in a sister pair. Climate divergence is 1 − Schoener's D, estimated based on climatic niche models predictions. ***p < 0.001; **p < 0.01; *p < 0.05.)