DOI: 10.5061/dryad.23j81
title: Data from: Parallels between two geographically and ecologically disparate cave invasions by the same species, Asellus aquaticus (Isopoda, Crustacea)

description: Caves are long-known examples of evolutionary replications where similar
 morphologies (troglomorphies) evolve independently as the result of strong
 natural selection of the extreme environment. Recently, this paradigm has
 been challenged based on observations that troglomorphies are inconsistent
 across taxa and different subterranean habitats. We investigated the
 degree of replicated phenotypic change in two independent cave invasions
 by the freshwater isopod Asellus aquaticus; the first in a sulphidic
 aquifer in Romania, the second in a sinking river in the Dinaric Karst in
 Slovenia. Both ancestral surface populations still live alongside the
 subterranean ones. Phylogenetic analyses show independence of the two
 colonization events, and microsatellite analysis shows no evidence of
 ongoing genetic exchange between surface and subterranean ecomorphs. The
 overall morphology has changed dramatically at both sites (50 of 62
 morphometric traits). The amount of phenotypic change did not reflect
 differences in genetic diversity between the two ancestral populations.
 Multivariate analyses revealed divergent evolution in caves, not parallel
 or convergent as predicted by the current paradigm. Still, 18 traits
 changed in a parallel fashion, including eye and pigment loss and antennal
 elongation. These changes might be a consequence of darkness as the only
 common ecological feature, because Romanian caves are chemoautotrophic and
 rich in food, whereas Slovenian caves are not. Overall, these results show
 that morphologically alike surface populations can diverge after invading
 different subterranean habitats, and that only about one-third of all
 changing traits behave as troglomorphies in the traditional sense.
description: Genotypes of Asellus
 aquaticus on 8 microsatellite lociDataset contains
 genotypes of surface and subterranean ecomorph pairs of Asellus aquaticus
 from Slovenia and Romania. 324 individuals were genotyped on 8
 microsatellite loci. Columns in the table: sampling site – site code on
 Figure 1 in the article; Voucher ID – sample name from the SubBioDatabase;
 alleles at each locus are recorded in separate columns. Missing data is
 recorded as "?".Genotypes ecomorphs Asellus
 aquaticus Slo_Rom.xlsxMorphometric data
 ecomorphs Asellus aquaticusMorphometric data: List
 of 60 traits used in morphometric analysis of surface and subterranean
 Asellus aquaticus ecomorphs from Slovenia and Romania. Means, standard
 deviations (SD) and standard errors (SE) of 60 morphometric traits (listed
 in Table A) in the surface and subterranean ecomorph pairs of Asellus
 aquaticus from Slovenia (PP/PR*) and Romania (MD/AW*). Asterisk (*)
 denotes the subterranean ecomorph relative to its ancestral surface
 form.Population genetics
 resultsPopulation genetics
 analysis: number of alleles, observed and expected heterozygosity, tests
 of Hardy-Weinberg equilibrium for each locus separately and linkage
 disequilibrium. Included are also results from Structure analysis of the
 Romanian samples.