Data from: Impact of Pleistocene climate on diversification and distribution of congeneric freshwater crustacean species

AimThe climatic oscillations of the glacial-interglacial cycles
significantly influenced species diversification, playing an essential
role in shaping the current patterns of biodiversity. However, the effects
of the Pleistocene climate on species diversification and their current
distribution are poorly understood for the Southern Hemisphere and some
taxonomic groups, such as invertebrates.  Here, we explore the
role of Pleistocene climate changes in the diversification and
distribution of four species of South American freshwater crustaceans.
LocationSouthern South America.  TaxonGenus Aegla (Aeglidae).
MethodsWe performed phylogenetic analyses, estimated genetic diversity,
and neutrality indices for Aegla alacalufi, Aegla neuquensis, Aegla
platensis, and Aegla uruguayana using nuclear and mitochondrial sequences.
We used the mitochondrial genes to estimate divergence times, calculate
historical demography, and reconstruct the ancestral area range. We also
estimated current and past potential distributions using ecological niche
modeling. ResultsAlthough all species studied had their diversification
influenced by Pleistocene glacial cycles, the Patagonian species A.
alacalufi and A. neuquensis, which were directly influenced by the glacial
ice cap, appear to have benefited from lower sea levels and melting of
glaciation ice. As for the species A. platensis and A. uruguayana, their
diversification was affected by the dry and cold climate on the continent
during the glacial period. Main ConclusionsOur study unveils the intricate
interplay between Pleistocene climatic fluctuations and the evolutionary
history of freshwater crustaceans in South America. Distinct
phylogeographic patterns were observed in Aegla. Some underwent
significant diversification due to glaciation, while the cold, arid
conditions of the continent shaped others. These findings underscore the
crucial role of past climate dynamics in the distribution and genetic
diversity of species. As freshwater ecosystems confront escalating
threats, our study highlights the urgency for conservation measures and
continued research to unveil species' adaptive mechanisms in the face
of climate change.