Neogene–Quaternary tectonic, eustatic and climatic events shaped the evolution of a South American treefrog

Abstract

Aim Understanding how past geological and climatic events could have generated intraspecific genetic variation at different temporal and spatial scales in the Neotropics requires a model encompassing distinct ecoregions. Because Anura species have their evolutionary history affected by climate and environmental changing, it is a suitable model to investigate the signatures of Neotropical historical events in species populations. Here we used a treefrog species to test hypotheses associated with tectonic, eustatic and climatic events along with isolation‐by‐environment and isolation‐by‐distance spatial patterns in genetic diversity. Taxon Scinax squalirostris (Lutz, 1925), Anura: Hylidae. Location Atlantic Forest, Cerrado, Chaco, Uruguayan Savanna and Pampas ecoregions in South America. Methods We sequenced nuclear and mitochondrial data from 219 individuals of S. squalirostris sampled at 26 locations in South America. We performed statistical phylogeographic analyses and reconstruction of spatiotemporal dispersal dynamics. Ecological niche modelling was conducted to predict spatial changes in environmental suitability from the Last Glacial Maximum to the Holocene and present day. Results We recovered a significant phylogeographic break roughly dated back to the Miocene (~7.6 Ma), coinciding with the retraction of marine incursions in the Paraná basin. Most dispersal events occurred in cooler periods of the Pliocene–Pleistocene transition. The spatial pattern in genetic diversity was not correlated with geographical distance or environmental variables. Main Conclusions Scinax squalirostris had a quasi‐stable distribution through time. Neogene–Quaternary tectonic, eustatic and climatic events drove the demographic history and dispersal dynamics of species, with a phylogeographical break dated to the Miocene coinciding with retractions of marine incursions in the Paraná basin. Lineage dispersal spread from the southern Atlantic Forest and retrieved gene flow signals congruent with the cold periods of the Pliocene and Pleistocene.

Comparative phylogeography shows congruent co‐divergence in Neotropical seasonally dry forest and savanna tree species

“…Our findings showed that the last glacial cycle (LGC) had an important role in shaping phylogeographical patterns and spatial distribution of genetic diversity in savanna and SDTF plant species, despite ancient species divergence during the Miocene, a pattern commonly recovered in phylogeography in South American species (e.g. Abreu‐Jardim et al., 2023; Miranda et al., 2019). We recovered a co‐divergence between species c .…”

“…Our findings showed that the last glacial cycle (LGC) had an important role in shaping phylogeographical patterns and spatial distribution of genetic diversity in savanna and SDTF plant species, despite ancient species divergence during the Miocene, a pattern commonly recovered in phylogeography in South American species (e.g. Abreu-Jardim et al, 2023;Miranda et al, 2019). We recovered a co-divergence between species c. 30,000 years ago, in the Upper Pleistocene, during the last glaciation, regardless of the biome, meaning that, Ecoevolity could detect that during the LGC, the five TA B L E 2 Comparison of genetic diversity and demographic parameters for the 97 populations of the five species in Brazil for combined cpDNA data and for ITS nrDNA.…”

Geoclimatic drivers of diversification in the largest arid and semi‐arid environment of the Neotropics: Perspectives from phylogeography

“…Future phylogeographic studies in the Chaco may corroborate these findings in other taxa. A promising example is a study on the tree frog Scinax squalirostris (Abreu‐Jardim et al., 2023), which used demographic modelling and approximate Bayesian computation to identify a phylogeographic break dated to the late Miocene, likely corresponding to the end of a marine incursion. However the substantial age of this phenomenon may limit the amount of demographic information researchers can retrieve from genetic data.…”

Treefrog Diversity in the Neotropics: Phylogenetic Relationships of Scinaxini (Anura: Hylidae: Hylinae)

“…While the current article was in press, Abreu-Jardim et al (2023) published a phylogeographic analysis of Scinax squalirostris based on the same dataset of Abreu-Jardim et al (2021). Their results are consistent with the recognition of UCS Scinax sp.…”