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Urbanization has dramatic impacts on natural habitats and such changes may potentially drive local adaptation of urban populations. Behavioral change has been specifically shown to facilitate the fast adaptation of birds to changing environments, but few studies have investigated the genetic mechanisms of this process. Such investigations could provide insights into questions about both evolutionary theory and management of urban populations. In this study, we investigated whether local adaptation has occurred in urban populations of a Neotropical bird species, Coereba flaveola , specifically addressing whether observed behavioral adaptations are correlated to genetic signatures of natural selection. To answer this question, we sampled 24 individuals in urban and rural environments, and searched for selected loci through a genome-scan approach based on RADseq genomic data, generated and assembled using a reference genome for the species. We recovered 46 loci as putative selection outliers, and 30 of them were identified as associated with biological processes possibly related to urban adaptation, such as the regulation of energetic metabolism, regulation of genetic expression, and changes in the immunological system. Moreover, genes involved in the development of the nervous system showed signatures of selection, suggesting a link between behavioral and genetic adaptations. Our findings, in conjunction with similar results in previous studies, support the idea that cities provide a similar selective pressure on urban populations and that behavioral plasticity may be enhanced through genetic changes in urban populations. [ABSTRACT FROM AUTHOR]

Wet and dry cyclical periods through the Pleistocene have been suggested as drivers of isolation and, consequently, divergence and expansions of populations associated with forest environments in the Neotropics. In northeastern Brazil, forests patches restricted to high altitudes led to the formation of regionally distinct ecosystems, known as "Atlantic Forest enclaves" or "brejos de altitude." Herein, we investigated the population history of the treefrog Dendropsophus oliveirai, a species associated with the Atlantic Forest and areas of enclaves in the Northeast region of the Brazil. We obtained sequences for one mitochondrial and two nuclear loci of 50 samples from 16 localities to investigate the population structure and demographic history across northeastern Atlantic Forest enclaves. Our data revealed that D. oliveirai exhibits three mtDNA haplogroups: low and highlands above the São Francisco River; low and highlands between Chapada Diamantina enclaves and northern populations of coastal Bahia and Sergipe States; lowlands below the Contas River. Divergence times estimates revealed that population splits occurred during the Pleistocene. Our data recovered low genetic differentiation between enclaves and lowland populations north and south of the São Francisco River, which supports a scenario of recent contact and repeated recolonization of enclaves by lowland populations during the humid Pleistocene phases. Species tree, and temporal and spatial population structures may indicate that D. oliveirai is actually a species complex. [ABSTRACT FROM AUTHOR]

Several species and morphotypes of Melipona are popularly known as "mandaçaia", even though they show distinctive patterns of tergal stripes among other peculiar features. In particular, Melipona mandacaia is often referred to as isolated populations of Melipona quadrifasciata with continuous tergal stripes from Northeastern Brazil, thus leading to biased estimates of their natural range and improper management of both species in meliponiculture. In order to put an end to this debate, we analyzed the genetic and ecological divergence among populations of these stingless bees in Brazilian semiarid region, sampled over six Brazilian states. Both approaches were congruent since they revealed a clear differentiation between M. quadrifasciata with continuous stripes and M. mandacaia, recovering each one as unique evolutionary units (highly-supported reciprocal monophyletic clades separated by 11 mutations and 1.8% of genetic divergence) without niche overlapping. These data highlight the importance of independent management for each group, particularly because M. mandacaia is one of the most commercially exploited bee species in traditional agriculture along northeastern Brazil. Moreover, the latter should be monitored in relation to their population viability since natural areas in Brazilian semiarid region have been increasingly deforested over the last decades. [ABSTRACT FROM AUTHOR]

We explored the effects of Quaternary climate changes on the campos rupestre sky island ecosystem in central and eastern Brazil studying the phylogeography of Richterago discoidea (Asteraceae) to better understand the effect of historical biogeographic processes on species diversification in this region. DNA sequences of nuclear (ITS) and plastid (psbA - trnH, rpl32 - trnL UAG , trnK UUU - rps16 and ycf3 - trnS) markers and 83 AFLP loci were used to genotype up to 90 individuals from 19 populations of R. discoidea. We investigated intraspecific genetic structure, demographic history and spatiotemporal diversification. Also, ecological niche modelling was used to infer palaeodistribution. Three lineages (without strong geographical structure) were identified in the Bayesian genetic structure analysis of 25 haplotypes, whereas AFLPs revealed two lineages with considerable levels of admixture. The origin of diversification of R. discoidea is on the Diamantina Plateau (Espinhaço Meridional, Minas Gerais), from where lineages expanded to the central highlands of Brazil during glacial periods in the Mid-Pleistocene. The current disjunct distribution is a relict of an ancient wide distribution, resulting from retraction during interglacial periods, confining populations to mountain-top sky islands that acted as refugia (Espinhaço Range and Goiás highlands). Expansion within refugium sites during the LGM blurred deeper genetic structure, and pressure of selection in ecological outliers favoured high genetic diversity outside refugia. © 2018 The Linnean Society of London, Biological Journal of the Linnean Society, 2018, YY, 000–000 [ABSTRACT FROM AUTHOR]