DOI: 10.5061/dryad.sj169
title: Data from: Ants exhibit asymmetric hybridization in a mosaic hybrid zone

description: Research on hybridization between species provides unparalleled insights
 into the pre- and post-zygotic isolating mechanisms that drive speciation.
 In social organisms, colony-level incompatibilities may provide additional
 reproductive barriers not present in solitary species, and hybrid zones
 offer an opportunity to identify these barriers. Here, we use
 genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone
 between two socially polymorphic ant species, Formica selysi and Formica
 cinerea. We characterize the zone, determine the frequency of hybrid
 workers, infer whether hybrid queens or males are produced, and
 investigate whether hybridization is influenced by colony social
 organization. We also compare cuticular hydrocarbon profiles and
 aggression levels between the two species. The hybrid zone exhibits a
 mosaic structure. The asymmetric distribution of hybrids skewed toward F.
 cinerea suggests a pattern of unidirectional nuclear gene flow from F.
 selysi into F. cinerea. The occurrence of backcrossed individuals
 indicates that hybrid queens and/or males are fertile, and the presence of
 the F. cinerea mitochondrial haplotype in 97% of hybrids shows that
 successful F1 hybrids will generally have F. cinerea mothers and F. selysi
 fathers. We found no evidence that social organization contributes to
 speciation, since hybrids occur in both single-queen and multiple-queen
 colonies. Strongly differentiated cuticular hydrocarbon profiles and
 heightened interspecific aggression further reveal that species
 recognition cues are both present and perceived. The discovery of fertile
 hybrids and asymmetrical gene flow is unusual in ants, and this hybrid
 zone will therefore provide an ideal system with which to investigate
 speciation in social insects.
description: CHCGraphSZThis file contains the graphical output of the GCMS runs for our 10 samples. The two samples from Aigle plus BRA1 and BRA2 are Formica cinerea (or F. cinerea-like hybrids), while BRA24 plus all samples from RID and FIN are Formica selysi (or F. selysi-like hybrids).1-BRA1This is the raw GCMS data for Formica cinerea colony BRA1. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.BRA2This is the raw GCMS data for Formica cinerea colony BRA2. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.5-RID33This is the raw GCMS data for Formica selysi colony RID33. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.7-FIN49This is the raw GCMS data for Formica selysi colony FIN49. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.9-RID59This is the raw GCMS data for Formica selysi colony RID59. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.8-FIN480This is the raw GCMS data for Formica selysi colony FIN480. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.6-RID53This is the raw GCMS data for Formica selysi colony RID53. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.3-AIGLEaThis is the raw GCMS data for Formica cinerea colony Aigle a. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.2-BRA24This is the raw GCMS data for Formica selysi colony BRA24. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.4-AIGLEbThis is the raw GCMS data for Formica cinerea colony Aigle b. The file is in .RAW format, which is compatible with Thermo Xcalibur, Micromass MassLynx, and Perkin Elmer TurboMass.Aggression_TrialsFile contains data on pairwise aggression trials. Columns include: Locality_W1 & Locality_W2 (collection localities of the two workers used in the trial), Origin_W1 & Origin W2 (species used in the trial), Score: aggression score 1-4, Aggressor_ID: for aggression scores of 3 or 4, we documented whether the initial aggressor was selysi, cinerea, or whether they were both aggressive at the same time.