Eliana Faria de Oliveira

Speciation with gene flow in whiptail lizards from a Neotropical xeric biome

Two main hypotheses have been proposed to explain the diversification of the Caatinga biota. The riverine barrier hypothesis (RBH) claims that the São Francisco River (SFR) is a major biogeographic barrier to gene flow. The Pleistocene climatic fluctuation hypothesis (PCH) states that gene flow, geographic genetic structure and demographic signatures on endemic Caatinga taxa were influenced by Quaternary climate fluctuation cycles. Herein, we analyse genetic diversity and structure, phylogeographic history, and diversification of a widespread Caatinga lizard (Cnemidophorus ocellifer) based on large geographical sampling for multiple loci to test the predictions derived from the RBH and PCH. We inferred two well‐delimited lineages (Northeast and Southwest) that have diverged along the Cerrado–Caatinga border during the Mid‐Late Miocene (6–14 Ma) despite the presence of gene flow. We reject both major hypotheses proposed to explain diversification in the Caatinga. Surprisingly, our results revealed a striking complex diversification pattern where the Northeast lineage originated as a founder effect from a few individuals located along the edge of the Southwest lineage that eventually expanded throughout the Caatinga. The Southwest lineage is more diverse, older and associated with the Cerrado–Caatinga boundaries. Finally, we suggest that C. ocellifer from the Caatinga is composed of two distinct species. Our data support speciation in the presence of gene flow and highlight the role of environmental gradients in the diversification process.

Estimating synchronous demographic changes across populations using hABC, and its application for a herpetological community from Northeastern Brazil

Many studies propose that Quaternary climatic cycles contracted and/or expanded the ranges of species and biomes. Strong expansion–contraction dynamics of biomes presume concerted demographic changes of associated fauna. The analysis of temporal concordance of demographic changes can be used to test the influence of Quaternary climate on diversification processes. Hierarchical approximate Bayesian computation (hABC) is a powerful and flexible approach that models genetic data from multiple species, and can be used to estimate the temporal concordance of demographic processes. Using available single‐locus data, we can now perform large‐scale analyses, both in terms of number of species and geographic scope. Here, we first compared the power of four alternative hABC models for a collection of single‐locus data. We found that the model incorporating an a priori hypothesis about the timing of simultaneous demographic change had the best performance. Second, we applied the hABC models to a data set of seven squamate and four amphibian species occurring in the Seasonally Dry Tropical Forests (Caatinga) in northeastern Brazil, which, according to paleoclimatic evidence, experienced an increase in aridity during the Pleistocene. If this increase was important for the diversification of associated xeric‐adapted species, simultaneous population expansions should be evident at the community level. We found a strong signal of synchronous population expansion in the Late Pleistocene, supporting the increase of the Caatinga during this time. This expansion likely enhanced the formation of communities adapted to high aridity and seasonality and caused regional extirpation of taxa adapted to wet forest.

Climatic suitability, isolation by distance and river resistance explain genetic variation in a Brazilian whiptail lizard

Spatial patterns of genetic variation can help understand how environmental factors either permit or restrict gene flow and create opportunities for regional adaptations. Organisms from harsh environments such as the Brazilian semiarid Caatinga biome may reveal how severe climate conditions may affect patterns of genetic variation. Herein we combine information from mitochondrial DNA with physical and environmental features to study the association between different aspects of the Caatinga landscape and spatial genetic variation in the whiptail lizard Ameivula ocellifera. We investigated which of the climatic, environmental, geographical and/or historical components best predict: (1) the spatial distribution of genetic diversity, and (2) the genetic differentiation among populations. We found that genetic variation in A. ocellifera has been influenced mainly by temperature variability, which modulates connectivity among populations. Past climate conditions were important for shaping current genetic diversity, suggesting a time lag in genetic responses. Population structure in A. ocellifera was best explained by both isolation by distance and isolation by resistance (main rivers). Our findings indicate that both physical and climatic features are important for explaining the observed patterns of genetic variation across the xeric Caatinga biome.

Amphibia, Anura, Leiuperidae, Physalaemus jordanensis Bokermann, 1967: distribution extension and geographic distribution map

The genus Physalaemus comprises 42 recognized species (Frost 2009) distributed from northern to southern South America east of the Andes. Physalaemus jordanensis Bokermann, 1967 belongs to Physalaemus gracilis group which currently includes five species: Physalaemus barrioi Bokermann, 1967, P. evangelistai Bokermann, 1967, P. gracilis (Boulenger, 1883), P. jordanensis and P. lisei Braun and Braun, 1977 (Nascimento et al. 2005). This group is distributed from southern to southeastern Brazil, Uruguay, northern Argentina and Paraguay, occurring at high altitudes (above 1,600 m), except P. gracilis (Nascimento et al. 2005; Frost, 2009) which also occurs at lower altitudes.

Amphibia, Anura, Physalaemus rupestris Caramaschi, Carcerelli and Feio, 1991: distribution extension and geographic distribution map

One of these groups, the Physalaemus deimaticus group, which includes Physalaemus erythros Caramaschi, Feio and Guimaraes-Neto, 2003, Physalaemus deimaticus Sazima and Caramaschi, 1988, and Physalaemus rupestris Caramaschi, Carcerelli and Feio, 1991 is restricted to high elevation inland montane fields, known as campos rupestres, in the state of Minas Gerais, southeastern Brazil. Physalaemus deimaticus and P. rupestris are know only from their type localities, at Serra do Cipo, municipality of Jaboticatubas and at Serra do Ibitipoca, municipality of Lima Duarte, respectively (Sazima and Caramaschi 1988; Caramaschi et al. 1991; Nascimento et al. 2005; Cruz and Feio 2007; Frost 2009). Recently, P. erythros were found at Serra do Caraca, municipality of Catas Altas, 33 Km northwards its type locality, at Serra do Itacolomi, municipality of Ouro Preto (Baeta and Silva 2009).

GEOGRAPHICAL DISTRIBUTION OF Ninia hudsoni (SERPENTES: DIPSADIDAE) WITH NEW OCCURRENCE RECORDS

Ninia hudsoni is a small neotropical snake with cryptic habits. Its distribution range is currently based on scattered literature records from Brazil, Ecuador, Guyana and Peru. Here we present an updated distribution map of N. hudsoni with two new records from southern Amazon and six unpublished records found in herpetological collections. We also implemented an ecological niche modeling (ENM) to predict climatically suitable areas for the occurrence of N. hudsoni . Both historical records and ENM support that N. hudsoni is restricted to the north, south and west edges of the Amazon. Southern Venezuela and northwestern Colombia seem to be the major gaps that lack occurrence records of N. hudsoni .

Align_NE.SW_R35_268.phased.sequeces

This file contains R35 aligned sequences used in most phylogeographic analyses: population assignment, haplotype genealogy, species tree estimation, migration estimate, species validation, and model based approach. Northeast (NE) sequences cluster was used separately in phylogeographic reconstruction.