Data from: Correlations between broad-scale taxonomic and genetic differentiations suggest a dominant imprint of historical processes on beta diversities

Aim: Dispersal limitation, environmental selection and drift are known to
influence both taxonomic similarity between communities and genetic
similarity between populations. However, disentangling the relative roles
of these processes on spatial patterns of differentiation - whether
regarding taxonomic differentiation between communities or genetic
differentiation between populations - is challenging. Investigating
whether spatial patterns of taxonomic differentiation and genetic
differentiation are correlated (β-SGDCs) is a promising approach to
address this issue. Here, we investigated β-SGDCs over broad spatial
scales and 22 freshwater fish species to elucidate the processes shaping
taxonomic and genetic differentiations between drainage basins. Location:
Global scope, data mainly from Europe and North America. Taxon:
Actinopterygii and Petromyzontiformes (freshwater fishes). Methods: We
used Mantel tests to investigate the raw correlation between taxonomic and
genetic differentiations. We carried out multiple regressions to
characterise the effects of geographic distance (proxy of dispersal
limitation), environmental distance (proxy of environmental selection) and
pairwise harmonic mean area between basins (proxy of drift) on taxonomic
differentiation and genetic differentiation taken separately. We then
analysed the correlation between the residuals of these two regressions
with Mantel tests. Finally, we investigated whether the variation in
β-SGDC between species was related to species traits. Results: We detected
an overall positive β-SGDC, both for the raw and the residual
correlations. This implies that, unmeasured effects, other than geographic
distance, environmental distance and harmonic mean area, influence the
β-SGDC observed. Values of β-SGDCs greatly varied between species, but
this was not explained by any species traits. Main conclusions:
Independently of the effects of geographic distance, environmental
distance and harmonic mean area, the β-SGDC we observed suggests that
historical processes strongly shaped the patterns of taxonomic and genetic
differentiations between basins. Consequently, taxonomic differentiation
may be an appropriate proxy to explain the influence of historical
processes on genetic differentiation.