DOI: 10.5061/dryad.js734c0
title: Data from: Genetic divergence and the number of hybridizing species affect the path to homoploid hybrid speciation

description: Hybridization is often maladaptive, and in some instances has led to the
 loss of biodiversity. However, hybridization can also promote speciation,
 such as during homoploid hybrid speciation, thereby generating
 biodiversity. Despite examples of homoploid hybrid species, the importance
 of hybridization as a speciation mechanism is still widely debated, and we
 lack a general understanding of the conditions most likely to generate
 homoploid hybrid species. Here we show that the level of genetic
 divergence between hybridizing species has a large effect on the
 probability that their hybrids evolve reproductive isolation. We find that
 populations of hybrids formed by parental species with intermediate levels
 of divergence were more likely to mate assortatively, and discriminate
 against their parental species, than those generated from weakly or
 strongly diverged parental species. Reproductive isolation was also found
 between hybrid populations, suggesting differential sorting of parental
 traits across populations. Finally, hybrid populations derived from three
 species were more likely to evolve reproductive isolation than those
 derived from two, supporting arguments that hybridization-supplied genetic
 diversity can lead to the evolution of novel “adaptive systems” and
 promote speciation. Our results illustrate when we expect hybridization
 and admixture to promote hybrid speciation. Whether homoploid hybrid
 speciation is a common speciation mechanism in general, remains an
 outstanding empirical question.
description: Dataset_S1-mate_countsData table listing the parental species used to generate a population of hybrids and the number of males that received matings during mate-choice experiments conducted en masse. The column "hyb_mate" gives the number of hybrid males from the same population as the females in a given experiment that females mated with. Each row reports the matings of a single hybrid population of females at 10 generations after the initial cross. Additional columns report results from statistical tests reported in the main text.Dataset_S1.csvDataset_S2-hybrid-v-hybrid-mate-countsMate counts for populations of admixed Drosophila given the choice to mate with males of their parental species, males from their same population, or males from an independent population derived from the same parental cross. Integers given in columns labeled "hybrid_1" and "hybrid_2" are used as identifiers of the hybrid population used in a given mate-choice experiment. Each row represents a single mate-choice experiment conducted en masse. Data are presented in Figure 2 of the main text.Dataset_S2.txtDataset_S3-tri-parental-mate-choiceMate counts for populations of admixed Drosophila produced by crossing three parental species. This data table reports the number matings occurring between hybrid females produced by crossing three parental species ("sp_1", "sp_2", and "sp_3") and each of the three parental male genotypes and hybrid male genotypes. Mating experiments were conducted 10 generations after the initial tri-parental cross. Each line reports mate choices of females from the same population of hybrids. Data are presented in Figure 3 of the main text.Dataset_S3.txt