@article{6f5a898a3748463eb0e39fc0eb81f237,
title = "The role of hybridization during ecological divergence of southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis)",
abstract = "Interactions between extrinsic factors, such as disruptive selection and intrinsic factors, such as genetic incompatibilities among loci, often contribute to the maintenance of species boundaries. The relative roles of these factors in the establishment of reproductive isolation can be examined using species pairs characterized by gene flow throughout their divergence history. We investigated the process of speciation and the maintenance of species boundaries between Pinus strobiformis and Pinus flexilis. Utilizing ecological niche modelling, demographic modelling and genomic cline analyses, we illustrated a divergence history with continuous gene flow. Our results supported an abundance of advanced generation hybrids and a lack of loci exhibiting steep transition in allele frequency across the hybrid zone. Additionally, we found evidence for climate-associated variation in the hybrid index and niche divergence between parental species and the hybrid zone. These results are consistent with extrinsic factors, such as climate, being an important isolating mechanism. A build-up of intrinsic incompatibilities and of coadapted gene complexes is also apparent, although these appear to be in the earliest stages of development. This supports previous work in coniferous species demonstrating the importance of extrinsic factors in facilitating speciation. Overall, our findings lend support to the hypothesis that varying strength and direction of selection pressures across the long lifespans of conifers, in combination with their other life history traits, delays the evolution of strong intrinsic incompatibilities.",
keywords = "conifers, ecological speciation, extrinsic barriers, hybrid zone, introgression, population genomics",
author = "Mitra Menon and Bagley, {Justin C.} and Friedline, {Christopher J.} and Whipple, {Amy V.} and Schoettle, {Anna W.} and Alejandro Leal-S{\`a}enz and Christian Wehenkel and Francisco Molina-Freaner and Lluvia Flores-Renter{\'i}a and Gonzalez-Elizondo, {M. Socorro} and Sniezko, {Richard A.} and Cushman, {Samuel A.} and Waring, {Kristen M.} and Eckert, {Andrew J.}",
note = "Funding Information: This research was funded by U.S. National Science Foundation (NSF) grants EF-1442486 (Eckert), PRFB-1306622 (Friedline) and EF-1442597 (Waring), as well as by Northern Arizona University{\textquoteright}s Technology Research Initiative Program, USDA Forest Service Forest Health Protection Gene conservation programme, USDA Forest Service National Fire Plan Award 01.RMRS.B.6 (Schoettle), Virginia Commonwealth University (VCU) Department of Biology and VCU Integrated Life Sciences. We thank Z. Gompert and T. Parchman for providing R code that aided plotting the BGC results. We also acknowledge the field sampling and laboratory work crew (see Appendix S1E). This work would not have been possible without generous computational resources provided by the VCU Center for High Performance Computing and the Brigham Young University Fulton Supercomputing Lab. Funding Information: USDA Forest Service National Fire Plan; National Science Foundation, Grant/Award Number: EF-1442486, EF-1442597; Northern Arizona University{\textquoteright}s Technology Research Initiative Program; Virginia Commonwealth University (VCU) Department of Biology and VCU Integrated Life Sciences Funding Information: This research was funded by U.S. National Science Foundation (NSF) grants EF-1442486 (Eckert), PRFB-1306622 (Friedline) and EF-1442597 (Waring), as well as by Northern Arizona University's Technology Research Initiative Program, USDA Forest Service Forest Health Protection Gene conservation programme, USDA Forest Service National Fire Plan Award 01.RMRS.B.6 (Schoettle), Virginia Commonwealth University (VCU) Department of Biology and VCU Integrated Life Sciences. We thank Z. Gompert and T. Parchman for providing R code that aided plotting the bgc results. We also acknowledge the field sampling and laboratory work crew (see Appendix S1E). This work would not have been possible without generous computational resources provided by the VCU Center for High Performance Computing and the Brigham Young University Fulton Supercomputing Lab. Funding Information: 1Integrative Life Sciences, Virginia Commonwealth University, Richmond, VA, USA 2Department of Biology, Virginia Commonwealth University, Richmond, VA, USA 3Departamento de Zoologia, Universidade de Bras{\'i}lia, Bras{\'i}lia, DF, Brazil 4Department of Biological Sciences and Merriam Powel Center for Environmental Research, Northern Arizona University, Flagstaff, AZ, USA 5Rocky Mountain Research Station, USDA Forest Service, Ft. Collins, CO, USA 6Programa Institucional de Doctorado en Ciencias Agropecuarias y Forestales, Universidad Ju{\'a}rez del Estado de Durango, Durango, Mexico 7Instituto de Silvicultura e Industria de la Madera, Universidad Juarez del Estado de Durango, Durango, Mexico 8Institutos de Geologia y Ecologia, Universidad Nacional Aut{\'o}noma de Mexico, Estaci{\'o}n Regional del Noroeste, Hermosillo, Sonora, Mexico 9Department of Biology, San Diego State University, San Diego, CA, USA 10Instituto Politecnico Nacional, CIIDIR, Durango, Durango, Mexico 11Dorena Genetic Resource Center, USDA Forest Service, Cottage Grove, OR, USA 12Rocky Mountain Research Station, USDA Forest Service, Flagstaff, AZ, USA Publisher Copyright: {\textcopyright} 2018 John Wiley & Sons Ltd",
year = "2018",
month = mar,
doi = "10.1111/mec.14505",
language = "English (US)",
volume = "27",
pages = "1245--1260",
journal = "Molecular Ecology",
issn = "0962-1083",
publisher = "Wiley-Blackwell",
number = "5",
}