Abstract
For species largely allopatric in distribution, zones of contact provide an opportunity for hybridization, testing grounds for species boundaries, and may result in the formation of a new species. Thus, hybrid zones have the potential to provide important insights into speciation. In this study, we performed a preliminary analysis of a hybrid zone between two subspecies of the dampwood termite, Zootermopsis nevadensis (Z. n. nuttingi and Z. n. nevadensis) near Bartle, CA, using 12 microsatellite loci and a mitochondrial gene. Fifty-seven colonies collected in 36 locations were analyzed. The analysis of genetic markers revealed a large hybrid zone approximately 104 km in width. Although stepped clines best explained the data, we are unable to rule out the existence of a mosaic hybrid zone. We inferred weak selection (s* < 0.05%) against hybrids, but the data also suggested the existence of a barrier to gene flow from Z. n. nevadensis to Z. n. nuttingi, but not in the other direction. Given the large zone of contact, extensive sampling is needed to obtain a more complete characterization of the hybrid zone. However, the results of this study suggest that despite the accumulation of phenotypic and genetic differences and time since divergence (~2 million years), Z. n. nuttingi and Z. n. nevadensis are capable of extensive hybridization.
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References
Aldrich B.T. and Kambhampati S. 2004. Microsatellite markers for two species of dampwood termites in the genus Zootermopsis (Isoptera: Termopsidae). Mol. Ecol. Notes 4: 719–721
Aldrich B.T. and Kambhampati S. 2007. Population structure and colony composition of two Zootermopsis nevadensis subspecies. Heredity 99: 443–451
Arnold M.L. 1997. Natural Hybridization and Evolution. Oxford Univ. Press: New York, NY
Avise J.C., Walker D. and Johns G.C. 1998. Speciation durations and Pleistocene effects on vertebrate phylogeography. Proc. R. Soc. Lond. B Biol. 265: 1707–1712
Barton N.H. 2000. Estimating multilocus linkage disequilibria. Heredity 84: 373–389
Barton N.H. and Baird S.J.E. 1995. ANALYSE: an application for analyzing hybrid zones. Freeware, Edinburgh. Available at http://helios.bto.ed.ac.uk/evolgen/mac/analyse
Barton N.H. and Gale K.S. 1993. Genetic analysis of hybrid zones. In: Hybrid Zones and the Evolutionary Process (Harrison R.G., Ed), Oxford Univ. Press: Oxford, UK. pp 13–45
Barton N.H. and Hewitt G.M. 1985. Analysis of hybrid zones. Annu. Rev. Ecol. Syst. 16: 113–148
Barton N.H. and Hewitt G.M. 1989. Adaptation, speciation, and hybrid zones. Nature 341: 497–503
Blum M.J. 2002. Rapid movement of a Heliconius hybrid zone: evidence for phase III of Wright’s shifting balance theory? Evolution 56: 1992–1998
Britch S.C., Cain M.L. and Howard D.J. 2001. Spatio-temporal dynamics of the Allonemobius fasciatus- A. socius mosaic hybrid zone: a 14-year perspective. Mol. Ecol. 10: 627–638
Broughton R.E. Jr. and Kistner D.H. 1991. A DNA hybridization study of the termite genus Zootermopsis (Isoptera: Termopsidae). Sociobiology 19: 15–40
Buño I., Torroja E., López-Fernández C., Butlin R.K., Hewitt G.M. and Gosálvez J. 1994. A hybrid zone between two subspecies of the grasshopper Chorthippus parallelus along the Pyrenees: the west end. Heredity 73: 625–634
Dasmahapatra K.K., Blum M.J., Aiello A., Hackwell S., Davies N., Berminghan E.P. and Mallet J. 2002. Inferences from a rapidly moving hybrid zone. Evolution 56: 741–753
Eggleton P. 2000. Global patterns of termite diversity. In: Termites: Evolution, Sociality, Symbioses, Ecology (Abe T., Bignell D.E. and Higashi M., Eds), Kluwer Academic Publishers: Dordrecht, The Netherlands. 25–51 pp
Fel-Clair F., Catalan J., Lenormand T. and Britton-Davidian J. 1998. Centromeric incompatibilities in the hybrid zone between house mouse subspecies from Denmark: evidence from patterns of nor activity. Evolution 52: 592–603
Goudet J. 1995. F-STAT Version 1.2: a computer program to calculate F-statistics. J. Hered. 86: 485–486
Harrison R.G. 1990. Hybrid zones: windows on the evolutionary process. Oxford Surv. Evol. Biol. 7: 69–128
Haverty M.I. and Thorne B.L. 1989. Agonistic behavior correlated with hydrocarbon phenotypes in dampwood termites, Zootermopsis (Isoptera: Termopsidae). J. Insect Behav. 2: 523–543
Haverty M.I., Page M., Nelson L.J. and Blomquist G.J. 1988. Cuticular hydrocarbons of dampwood termites, Zootermopsis: intra- and intercolony variation and potential as taxonomic characters. J. Chem. Ecol. 14: 1035–1058
Hewitt G.M. 1996. Some genetic consequences of ice ages, and their role in divergence and speciation. Biol. J. Linn. Soc. 58: 247–276
Hewitt G.M. 2000. The genetic legacy of the quaternary Ice Ages. Nature 405: 907–913
Kambhampati S. and Peterson A.T. 2007. Ecological niche conservation and differentiation in the wood-feeding cockroaches, Cryptocercus, in the United States. Biol. J. Linn. Soc. 90: 457–466
Largiadèr C.R., Klingenberg C.P. and Zimmermann M. 1994. Morphometric variation in a hybrid zone of two subspecies of Gerris costae (Heteroptera: Gerridae) in the Maritime Alps. J. Evol. Biol. 7: 697–712
Lepage M. and Darlington J.P.E.C. 2000. Population dynamics of termites. In: Termites: Evolution, Sociality, Symbioses, Ecology (Abe T., Bignell D.E. and Higashi M., Eds), Kluwer Academic Publishers: Dordrecht, The Netherlands. pp 333–361
Mallett J., Barton N., Lamas G.M., Santisteban J.C., Musedas M.M. and Eeley H. 1990. Estimates of selection and gene flow from measures of cline width and linkage disequilibrium in Heliconius hybrid zones. Genetics 124: 921–936
Phillips B.L., Baird S.J.E. and Moritz C. 2004. A narrow zone of secondary contact between morphologically cryptic phylogeographic lineages of the rainforest skink, Carlia rubrigularis. Evolution 58: 1536–1548
Porter A.H., Wenger R., Geiger H., Scholl A. and Shapiro A.M. 1997. The Pontia daplidice-edusa hybrid zone in northwestern Italy. Evolution 51: 1561–1573
Pritchard J.K., Stephens M. and Donnelly P.J. 2000. Inference of population structure using multilocus genotype data. Genetics 155: 945–959
Queller D.C. and Goodnight K.F. 1989. Estimating relatedness using genetic markers. Evolution 43: 258–275
Rand D.M. and Harrison R.G. 1989. Ecological genetics of a mosaic hybrid zone: mitochondrial, nuclear, and reproductive differentiation of crickets by soil type. Evolution 43: 432–449
Ross C.L. and Harrison R.G. 2002. A fine-scale analysis of the mosaic hybrid zone between Gryllus firmus and Gryllus pennsylvanicus. Evolution 56: 2296–2312
Rousset F. 1997. Genetic differentiation and estimation of gene flow from F-statistics under isolation by distance. Genetics 145: 1219–1228
Sequeira F., Alexandrino J., Rocha S., Arntzen J.W. and Ferrand N. 2005. Genetic exchange across a hybrid zone within the Iberian endemic golden-striped salamander, Chioglossa lusitanica. Mol. Ecol. 14: 245–254
Sites J.W. Jr., Nicholas H.B. and Reed K.M. 1995. The genetic structure of a hybrid zone between two chromosome races of the Sceloporus grammicus complex (Sauria, Phrynosomatidae) in central Mexico. Evolution 49: 9–36
Smadja C., Catalan J. and Ganem G. 2004. Strong premating divergence in a unimodal hybrid zone between two subspecies of house mouse. J. Evol. Biol. 17: 165–176
Szymura J.M. and 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: 1141–1159
Szymura J.M. and Barton N.H. 1991. The genetic structure of the hybrid zone between the fire-bellied toads Bombina bombina and B. variegata: Comparisons between transects and loci. Evolution 45: 237–261
Thorne B.L., Haverty M.I., Page M. and Nutting W.L. 1993. Distribution and biogeography of the North American termite genus Zootermopsis (Isoptera: Termopsidae). Ann. Entomol. Soc. Am. 86: 532–544
Vargo E.L. 2003. Hierarchical analysis of colony and population genetic structure in the eastern subterranean termite, Reticulitermes flavipes, using two classes of molecular markers. Evolution 57: 2805–2818
Vines T.H., Köhler S.C., Thiel M., Ghira I., Sands T.R., MacCallum C.J., Barton N.H. and Nürnberger B. 2003. The maintenance of reproductive isolation in a mosaic hybrid zone between the fire-bellied toads Bombina bombina and B. variegata. Evolution 57: 1876–1888
Wake D.B. 1997. Incipient species formation in salamanders of the Ensatina complex. Proc. Natl. Acad. Sci. USA 94: 7761–7767
Wang H., McArthur E.D. and Freeman D.C. 1999. Narrow hybrid zone between two subspecies of big sagebrush (Artemisia tridentata: Asteraceae). IX. Elemental uptake and niche separation. Am. J. Bot. 86: 1099–1107
Acknowledgments
We thank M. Haverty for alerting us to the presence and location of the hybrid zone between the two subspecies. We thank M. Haverty and L. Nelson for identifying and help in collecting Zootermopsis. Without their help, this study would not have been possible. We thank E. Krafsur and B. Thorne for helpful comments. We thank E. Vargo C. DeHeer, and J. Marshall for reviewing earlier versions of this manuscript and providing constructive criticism. The distribution map was prepared by the Geographic Information Systems Spatial Analysis Laboratory (GISSAL), Department of Geography, Kansas State University. This study was funded by a National Science Foundation grant (DEB9806710 to S. K.). This is journal article number 10-050-J of the Kansas Agricultural Experiment Station.
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Aldrich, B.T., Kambhampati, S. Preliminary analysis of a hybrid zone between two subspecies of Zootermopsis nevadensis . Insect. Soc. 56, 439–450 (2009). https://doi.org/10.1007/s00040-009-0041-1
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DOI: https://doi.org/10.1007/s00040-009-0041-1