Dwarf geckos and giant rivers: the role of the São Francisco River in the evolution of Lygodactylus klugei (Squamata: Gekkonidae) in the semi-arid Caatinga of north-eastern Brazil

2019 ◽  
Vol 129 (1) ◽  
pp. 88-98
Author(s):  
Flávia M Lanna ◽  
Marcelo Gehara ◽  
Fernanda P Werneck ◽  
Emanuel M Fonseca ◽  
Guarino R Colli ◽  
...  
Keyword(s):  
Gene Flow ◽  
Assignment Test ◽  
Nuclear Markers ◽  
Sao Francisco River ◽  
Eastern Brazil ◽  
São Francisco River ◽  
North Eastern ◽  
Multilocus Approach ◽  
Geomorphological Features

Abstract Species diversification can be strongly influenced by geomorphological features, such as mountains, valleys and rivers. Rivers can act as hard or soft barriers to gene flow depending on their size, speed of flow, historical dynamics and regional topographical characteristics. The São Francisco River (SFR) is the largest perennial river in the Caatinga biome in north-eastern Brazil and has been considered a barrier to gene flow and dispersal. Herein, we evaluated the role of the SFR on the evolution of Lygodactylus klugei, a small gecko from the Caatinga. Using a single-locus species delimitation method (generalized mixed Yule coalescent), we defined lineages (haploclades). Subsequently, we evaluated the role of the SFR in structuring genetic diversity in this species using a multilocus approach to quantify migration across margins. We also evaluated genetic structure based on nuclear markers, testing the number of populations found through an assignment test (STRUCTURE) across the species distribution. We recovered two mitochondrial lineages structured with respect to the SFR, but only a single population was inferred from nuclear markers. Given that we detected an influence of the SFR only on mitochondrial markers, we suggest that the current river course has acted as a relatively recent geographical barrier for L. klugei, for ~450 000 years.

Is the São Francisco River a geographic barrier to gene flow in trees of Handroanthus ochraceus?

2013 ◽  
Vol 29 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Patrícia de Abreu Moreira ◽  
G. Wilson Fernandes
Keyword(s):  
Gene Flow ◽  
Genetic Relatedness ◽  
Left Bank ◽  
Geographic Barrier ◽  
Sao Francisco River ◽  
Seasonally Dry ◽  
Eastern Brazil ◽  
São Francisco River ◽  
The Right ◽  
Two Populations

Abstract:Many landscape features represent geographic barriers to gene flow, and promote genetic discontinuity. Rivers are effective barriers. However, most studies on this subject have focused on animals and only a few have focused on plants. We studied the genetic structure and gene flow of the tropical tree Handroanthus ochraceus (Bignoniaceae) on both banks of the São Francisco River in a Brazilian seasonally dry tropical forest. The São Francisco is located in eastern Brazil and is 600 m wide at the study site. Our hypothesis was that the river is a geographic barrier to gene flow of H. ochraceus trees. We sampled two populations on the left bank and one population on the right bank. We used seven microsatellites to genotype 212 individual plants. All populations had low polymorphism and genetic diversity, but high inbreeding. There was no genetic differentiation among populations and, consequently, the estimated gene flow was high for all pairs of populations. The genetic relatedness among individuals from populations of the same margin did not differ from the relatedness among individuals from populations of opposite margins. Hence, the São Francisco River is not an effective geographic barrier to gene flow among H. ochraceus populations.

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

Organic matter in the deltaic clinoform of the São Francisco River (Eastern Brazil)

2019 ◽  
Vol 40 (6) ◽  
pp. 879-895 ◽  
Author(s):  
Narayana Flora Costa Escobar ◽  
José Maria Landim Dominguez ◽  
Maria do Rosário Zucchi ◽  
Antônio Expedito Gomes de Azevedo ◽  
Adriane Gonçalves de Araújo Nunes Rangel ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sao Francisco River ◽  
Eastern Brazil ◽  
São Francisco River

Challenge and response in the São Francisco River Basin

Water Policy ◽  
2014 ◽  
Vol 16 (S1) ◽  
pp. 153-200 ◽  
Author(s):  
Hannah Lee ◽  
Zamyla Chan ◽  
Kai Graylee ◽  
Arani Kajenthira ◽  
Daniela Martínez ◽  
...  
Keyword(s):  
Special Focus ◽  
Policy Debate ◽  
Management Framework ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Depth Analysis ◽  
Major River ◽  
Set Up ◽  
Development And Management

The São Francisco River has been, and continues to be, the only major river in arid Northeast Brazil and, as such, continues to be a major focus for development policy in this poorest part of the country. In a context of persistent water scarcity and recurring drought, the imperative is to develop a water development and management framework capable of simultaneously creating a platform for growth, dealing with distributive conflicts and ensuring rational usage. Addressing this challenge has been complicated by the multi-layered institutions of Brazilian federalism. This paper traces the development of the institutional framework for water management in the São Francisco Basin, highlighting the role of both local innovation and the pressures of federal centralization. The single most important policy debate currently affecting the basin is an ambitious inter-basin transfer project that aims to provide secure water supply to major cities and irrigation projects in neighboring basins. The paper provides an in-depth analysis of the project, with a special focus on understanding the policy process underpinning the project. This analysis anchors the discussion in the difficult dilemmas currently faced by policymakers and gives some insights into the actual functioning of a complex and sometimes ambiguous institutional set-up.

scholarly journals MUDANÇAS AMBIENTAIS QUATERNÁRIAS NA PORÇÃO SUBMÉDIA DA PLANÍCIE DO SÃO FRANCISCO: RECONSTRUÇÃO AMBIENTAL

2017 ◽  
Vol 32 (3) ◽  
pp. 107
Author(s):  
Daniel Rodrigues de Lira
Keyword(s):  
General Circulation ◽  
Environmental Changes ◽  
Time Frame ◽  
Atmospheric Teleconnection ◽  
Sao Francisco River ◽  
River Floodplains ◽  
São Francisco River ◽  
Floodplain Deposits ◽  
The Last Glacial

A dinâmica dos acontecimentos geomorfológicos e sua evolução tornam-se necessárias para elucidar a história recente da paisagem. Nessa perspectiva a análise de depósitos superficiais permitiu a reconstrução das dinâmicas ambientais para a região com ênfase temporal/paleoambiental. Os Latossolos que integram a Planície do Rio São Francisco têm origem a partir do rebaixamento de suas águas e surgimento de barras arenosas retrabalhadas pelo vento em períodos de maior semiaridez formando campos de dunas; em períodos mais úmidos, mantos de areia, sendo estes retrabalhados em momentos de cheias, originando depósitos arenosos na planície fluvial. Os estudos indicam uma gênese climática controlada por fatores da circulação geral da atmosfera em nível global e regional, revelando tele conexões importantes desde o Último Máximo Glacial – UMG, transição Pleistoceno/Holoceno até o Holoceno Superior. QUATERNARY ENVIRONMENTAL CHANGES IN THE SUBMIDDLE REACH OF SÃO FRANCISCO RIVER FLOODPLAINS: AN ENVIRONMENTAL RECONSTRUCTION ABSTRACTThe analysis of superficial deposits allows the reconstruction the environmental dynamics of the study area within a given palaeo-environmental time frame. The Oxisols developed on the Sao Francisco floodplain deposits, originate from the lowering of water-table levels in the river banks and the subsequent emergence of sandy bars, some of which were reworked by wind erosion during periods of stronger semi-aridity, resulting in the accumulation of dune fields and sand mantles in wetter periods. Later on, some of these deposits were reworked by the floods of the São Francisco River. The results of this research point to a climatic genesis of landforms, driven by general circulation controls, thus revealing the role of important atmospheric teleconnection events in the area occurring since the Last Glacial Maximum – LGM, through the Pleistocene/Holocene transition until the Upper Holocene.Keywords: evolution of the landscape; superficial deposits; semiarid.

scholarly journals Significant Baseflow Reduction in the Sao Francisco River Basin

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 2
Author(s):  
Murilo Cesar Lucas ◽  
Natalya Kublik ◽  
Dulce B. B. Rodrigues ◽  
Antonio A. Meira Neto ◽  
André Almagro ◽  
...  
Keyword(s):  
River Basin ◽  
Water Scarcity ◽  
Agricultural Land ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Terrestrial Water ◽  
Long Term Trends ◽  
Storage Change

Water scarcity is a key challenge to global development. In Brazil, the Sao Francisco River Basin (SFB) has experienced water scarcity problems because of decreasing streamflow and increasing demands from multiple sectors. However, the drivers of decreased streamflow, particularly the potential role of the surface-groundwater interaction, have not yet been investigated. Here, we assess long-term trends in the streamflow and baseflow of the SFB during 1980–2015 and constrain the most likely drivers of observed decreases through a trend analysis of precipitation (P), evapotranspiration (ET), and terrestrial water storage change (TWS). We found that, on average, over 86% of the observed decrease in streamflow can be attributed to a significant decreasing baseflow trend along the SFR, with a spatial agreement between the decreased baseflow, increased ET, and irrigated agricultural land in the Middle SFB. We also noted a decreasing trend in TWS across the SFB exceeding –20 mm year−1. Overall, our findings indicate that decreasing groundwater contributions (i.e., baseflow) are providing the observed reduction in the total SFR flow. A lack of significant P trends and the strong TWS depletion indicate that a P variability only has likely not caused the observed baseflow reduction, in mainly the Middle and Sub-middle SFB. Therefore, groundwater and surface withdrawals may likely be a driver of baseflow reduction in some regions of the SFB.

scholarly journals Significant baseflow reduction in the Sao Francisco River Basin

2020 ◽  
Author(s):  
Murilo Cesar Lucas ◽  
Natalya Kublik ◽  
Dulce B. B. Rodrigues ◽  
Antonio A. Meira Neto ◽  
André Almagro ◽  
...  
Keyword(s):  
River Basin ◽  
Water Scarcity ◽  
Agricultural Land ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Terrestrial Water ◽  
Long Term Trends ◽  
Storage Change

Water scarcity is a key challenge to global development. In Brazil, the Sao Francisco River Basin (SFB) has experienced water scarcity problems because of decreasing streamflow and increasing demands from multiple sectors. However, the drivers of decreased streamflow, particularly the potential role of surface-groundwater interaction, have not been yet investigated. Here, we assess long-term trends in baseflow, quickflow, and streamflow of the SFB during 1980–2015 and constrain the most likely drivers of observed decreases through trend analysis of precipitation (P), evapotranspiration (ET), and terrestrial water storage change (TWS). We found that over 82% of the observed decrease in streamflow can be attributed to a significant decreasing baseflow trend (< -20 m3 s-1 y-1) along the SFR with spatial agreement between decreased baseflow, increased ET, and irrigated agricultural land. We also noted a decrease in TWS across the SFB with trends exceeding -20 mm y-1. Overall, our findings indicate that decreasing groundwater contributions (i.e., baseflow) is providing the observed reduction in total SFR flow. A lack of significant P trends indicates that only P variability likely has not caused the observed baseflow reduction, mainly in the Middle and Sub-middle SFB. Therefore, groundwater and surface withdrawals may be likely a driver of water scarcity over the SFB.

scholarly journals Genetic Diversity in Populations of Mediterranean Fruit Flies in North-Eastern Brazil

2022 ◽  
Vol 14 (2) ◽  
pp. 70
Author(s):  
Jéssica S. Cardoso ◽  
Sâmela S. Mendes ◽  
Ana Maria Waldschmidt ◽  
Maria Aparecida Castellani ◽  
Iara S. Joachim-Bravo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Issr Markers ◽  
Fruit Flies ◽  
Regional Strategies ◽  
Eastern Brazil ◽  
North Eastern ◽  
Control And Management

This study aimed at determining the population genetic structure of Mediterranean fruit flies (Ceratitis capitata) in North-eastern Brazil, so as to improve our understanding of the viability of the inter-simple sequences repeat (ISSR) markers in Brazilian populations, along with inferences on population genetic composition which can be used in management programs. For this, ISSR markers were used in groups collected from four municipalities in this region. Primers were polymorphic, revealing moderate expected heterozigosity, with 80% of the variation occurring within populations and moderate structure. Bayesian analysis revealed K = 3, consistent with pairwise FST and indicating low structure between Barra do Choça and Planalto, and moderate structure between Caraíbas and Planalto. Data indicated high diversity, suggesting two interpretations: the analyzed populations arose from a single population and are now under structuring processes, or populations had different origins, but are currently connected by gene flow. Thus, ISSR primers were affective in obtaining information about genetic structure of C. capitata populations in North-eastern Brazil, as evidenced by high polymorphism and separation or grouping of populations according to their allelic compositions. Furthermore, this paper provides useful information for understanding the genetic diversity, population structure and gene flow of C. capitata populations in this region and developing regional strategies for the control and management of the species.

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