DOI: 10.5061/dryad.8dq043h
title: Data from: Species diversification in a lineage of Mexican red oak (Quercus section Lobatae subsection Racemiflorae)—the interplay between distance, habitat, and hybridization

description: In widespread taxa in which hybridization is suspected of being an
 important aspect of species biology, the patterns and drivers of lineage
 diversification are not always clear. Here, we examine the patterns of
 species diversification in a monophyletic lineage of oaks endemic to
 western Mexico, a center of global oak diversity. This group of four
 species inhabits a variety of soil types and exhibits varying patterns of
 species distribution ranging from widespread to restricted, with the range
 bisected by the Trans-Mexican Volcanic Belt (TVB). Using chloroplast and
 nuclear microsatellites, we evaluated genetic diversity, diversification,
 and genetic group assignment across 49 populations. Chloroplast data
 identified 29 haplotypes in three distinct lineages, many of these found
 occurring on opposite sides of the TVB. Individual species were only
 loosely associated to specific chloroplast haplotypes but the distribution
 of shared haplotypes supports a one-time wider distribution. One lineage
 was highly divergent and geographically isolated, likely representing a
 case of chloroplast capture via hybridization and may indicate a range
 expansion of Racemiflorae into new territory. Nuclear gene diversity
 varied little across species and populations; however, differentiation and
 genetic assignment analysis was strongly structured geographically and
 tended to cluster with broad soil types. Soil specialist taxa produced
 homogeneous genetic structure while soil generalists showed varying
 patterns of mixed ancestry and high levels of admixture. Speciation
 appears driven by a combination of distance and edaphic factors leading to
 drift. Hybridization appears to be complementary, occurring most often in
 non-specific soil environments and in marginal areas, and contributes to a
 long-scale pattern of gene exchange as species ranges fluctuate with time.
description: Racemiflorae_Chloroplast_ARLEQUINChloroplast microsatellite data in ARLEQUIN format for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Chloroplast_GENALEXChloropast microsatellite data in GENALEX format for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Chloroplast_GENEPOPChloroplast microsatellite data in GENEPOP format for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Chloroplast_CPssr inputInput file for CPssr software. Chloroplast microsatellite haplotype data for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Nuclear_GENALEXNuclear microsatellite data in GENALEX format for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Nuclear_GENEPOPNuclear microsatellite data in GENEPOP format for 49 populations of Quercus section Lobatae subsection Racemiflorae.Racemiflorae_Nuclear_STRUCTUREInput file for STRUCTURE of nuclear microsatellites for 49 populations of Quercus section Lobatae subsection Racemiflorae.