Late Pleistocene climatic changes promoted demographic expansion and population reconnection of a Neotropical savanna-adapted bird, Neothraupis fasciata (Aves: Thraupidae)

Abstract

We performed phylogeographic and genetic structure analyses of Neothraupis fasciata joined with species distribution modelling to evaluate whether: (1) the distribution of genetic variability shows a pattern expected by the isolation-by-distance model; (2) the influence of the Pleistocene climate changes on species distribution; and (3) climate/climatic stability (hypothesis of climatic stability) as a predictor of population genetic diversity. Based on two molecular datasets (ND2 and FIB-5), the isolation-by-distance hypothesis was not supported. The mitochondrial haplotype network indicated the existence of historically isolated populations at the southern range of the species distribution, and recent population expansion was identified by both neutrality tests and extended Bayesian skyline plot analysis. Thus, the climatic changes during the Pleistocene might have promoted the reconnection of the partially isolated southern populations, which may have persisted in the plateaus during the cycles of savanna contractions. Subsequently, this species (re)colonized northern areas of the species present distribution, following the continuous vegetation on the São Francisco and Central plateaus about 60 kyr, and also reached the Amazonian savannas likely via the central corridor. Thus, our results indicated that the intrinsic relationship between the relief heterogeneity (plateaus and depressions) and the climatic fluctuations, mainly in the Pleistocene, promoted population reconnection and demographic expansion of N. fasciata.

Pleistocene climatic oscillations associated with landscape heterogeneity of the South American dry diagonal explains the phylogeographic structure of the narrow‐billed woodcreeper (Lepidocolaptes angustirostris, Dendrocolaptidae)

“…Our results are in accordance with other studies that found evidence of retraction of South American open biomes during warmer interglacial periods, and expansion during cold and dry glacial periods (Bueno et al , Lima‐Rezende et al ). As consequence of this spatio‐temporal dynamic of suitable areas, it can be expected that individuals evolved in isolation under different climatic and ecological pressures, and action of the genetic drift, accumulating differences that can limit gene flow between these lineages at the limits of respectively suitable areas after niche and population expansions (Hewitt ).…”

“…Secondarily, the heterogeneous landscape along the dry diagonal may have being limiting gene flow among the genetic lineages after contact was re-established among them. Thus, our results are in agreement with other studies (Lima-Rezende et al 2019, Silva et al 2019 indicating that Pleistocene climatic oscillations have had a strong influence in the intraspecific divergence of dry diagonal avifauna. Our results reinforce the initial proposition of Pennington et al (2000), then stressed by others (Werneck et al 2012, Fouquet et al 2014, that the different biomes of the dry diagonal should be considered as independent units from the biogeographical point of view.…”

“…The gene flow between these lineages was geographically restricted at the border of the lineage ranges, suggesting that the barriers to gene flow between these biomes are efficient, but less effective than those between the lineages from Cerrado and Caatinga. It is not possible to identify an evident geographical barrier between the lineage of Cerrado; however, it may be associated with the landscape compartmentalization of Cerrado, as observed in a tanager ( Neothraupis fasciata , Lima‐Rezende et al ) and a lizard ( Micrablepharus atticolus , Santos et al ) species. The gene flow between the E_Cerrado and Chaco lineages was observed in an STDF patch (Serra da Bodoquena, LOC 27, Fig.…”

“…in plants, Ramos et al , Caetano et al ; and insects, Moraes et al ). Even though birds are the most diverse group of land vertebrates in the Neotropical region (Stotz et al ), few studies have focused on their intraspecific evolution in the dry diagonal (Leite et al , Savit and Bates , Moura et al , Lima‐Rezende et al ), mostly because early studies found very low intraspecific differentiation in open area birds (Bates et al ).…”

A general scenario to evaluate evolution of grassland birds in the Neotropics

“…Phylogeographical studies on organisms inhabiting grasslands in the Neotropics are still in their infancy (Bates et al 2003, Masello et al 2011, Campagna et al 2012a, 2012b, Lopes et al 2018, Moura et al 2018, Norambuena et al 2018, Lima-Rezende et al 2019, Corbett et al 2020, Rocha et al 2020, Santana et al 2020, limiting our understanding of the potential historical scenarios that characterize these ecosystems as well as the potential processes shaping genetic diversity across taxa. Therefore, new information about the phylogeographical history of taxa that specialize in this type of habitat is crucial to understand the historical and geological processes that have shaped the biodiversity of this biome (Antonelli et al 2010, Brumfield 2012.…”