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Guillory WX, de Medeiros Magalhães F, Coelho FEA, Bonatelli IAS, Palma-Silva C, Moraes EM, Garda AA, Burbrink FT, Gehara M. Geoclimatic drivers of diversification in the largest arid and semi-arid environment of the Neotropics: Perspectives from phylogeography. Mol Ecol 2024; 33:e17431. [PMID: 38877815 DOI: 10.1111/mec.17431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/16/2024]
Abstract
The South American Dry Diagonal, also called the Diagonal of Open Formations, is a large region of seasonally dry vegetation extending from northeastern Brazil to northern Argentina, comprising the Caatinga, Cerrado, and Chaco subregions. A growing body of phylogeography literature has determined that a complex history of climatic changes coupled with more ancient geological events has produced a diverse and endemic-rich Dry Diagonal biota. However, the exact drivers are still under investigation, and their relative strengths and effects are controversial. Pleistocene climatic fluctuations structured lineages via vegetation shifts, refugium formation, and corridors between the Amazon and Atlantic forests. In some taxa, older geological events, such as the reconfiguration of the São Francisco River, uplift of the Central Brazilian Plateau, or the Miocene inundation of the Chaco by marine incursions, were more important. Here, we review the Dry Diagonal phylogeography literature, discussing each hypothesized driver of diversification and assessing degree of support. Few studies statistically test these hypotheses, with most support drawn from associating encountered phylogeographic patterns such as population structure with the timing of ancient geoclimatic events. Across statistical studies, most hypotheses are well supported, with the exception of the Pleistocene Arc Hypothesis. However, taxonomic and regional biases persist, such as a proportional overabundance of herpetofauna studies, and the under-representation of Chaco studies. Overall, both Pleistocene climate change and Neogene geological events shaped the evolution of the Dry Diagonal biota, though the precise effects are regionally and taxonomically varied. We encourage further use of model-based analyses to test evolutionary scenarios, as well as interdisciplinary collaborations to progress the field beyond its current focus on the traditional set of geoclimatic hypotheses.
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Affiliation(s)
- Wilson X Guillory
- Department of Earth and Environmental Sciences, Rutgers University Newark, Newark, New Jersey, USA
- Department of Biological Sciences, Rutgers University Newark, Newark, New Jersey, USA
| | | | | | - Isabel A S Bonatelli
- Departamento de Ecologia e Biologia Evolutiva, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, São Paulo, Brazil
| | - Clarisse Palma-Silva
- Departamento de Biologia Vegetal, Universidade Estadual de Campinas, Cidade Universitária Zeferino Vaz, Campinas, São Paulo, Brazil
| | - Evandro M Moraes
- Departamento de Biologia, Universidade Federal de São Carlos (UFSCar), Sorocaba, São Paulo, Brazil
| | - Adrian Antonio Garda
- Departamento de Botânica e Zoologia, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Frank T Burbrink
- Department of Herpetology, The American Museum of Natural History, New York City, New York, USA
| | - Marcelo Gehara
- Department of Earth and Environmental Sciences, Rutgers University Newark, Newark, New Jersey, USA
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Nazareno AG, Knowles LL, Dick CW, Lohmann LG. By Animal, Water, or Wind: Can Dispersal Mode Predict Genetic Connectivity in Riverine Plant Species? FRONTIERS IN PLANT SCIENCE 2021; 12:626405. [PMID: 33643353 PMCID: PMC7907645 DOI: 10.3389/fpls.2021.626405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/06/2021] [Indexed: 05/08/2023]
Abstract
Seed dispersal is crucial to gene flow among plant populations. Although the effects of geographic distance and barriers to gene flow are well studied in many systems, it is unclear how seed dispersal mediates gene flow in conjunction with interacting effects of geographic distance and barriers. To test whether distinct seed dispersal modes (i.e., hydrochory, anemochory, and zoochory) have a consistent effect on the level of genetic connectivity (i.e., gene flow) among populations of riverine plant species, we used unlinked single-nucleotide polymorphisms (SNPs) for eight co-distributed plant species sampled across the Rio Branco, a putative biogeographic barrier in the Amazon basin. We found that animal-dispersed plant species exhibited higher levels of genetic diversity and lack of inbreeding as a result of the stronger genetic connectivity than plant species whose seeds are dispersed by water or wind. Interestingly, our results also indicated that the Rio Branco facilitates gene dispersal for all plant species analyzed, irrespective of their mode of dispersal. Even at a small spatial scale, our findings suggest that ecology rather than geography play a key role in shaping the evolutionary history of plants in the Amazon basin. These results may help improve conservation and management policies in Amazonian riparian forests, where degradation and deforestation rates are high.
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Affiliation(s)
- Alison G. Nazareno
- Departamentos de Botânica, Universidade de São Paulo, São Paulo, Brazil
- Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Alison G. Nazareno,
| | - L. Lacey Knowles
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States
| | - Christopher W. Dick
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Lúcia G. Lohmann
- Departamentos de Botânica, Universidade de São Paulo, São Paulo, Brazil
- Lúcia G. Lohmann,
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