Filogeografia da espécie Subulo gouazoubira (Mammalia: Cervidae) na Caatinga
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2023-03-31
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Universidade Estadual Paulista (Unesp)
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A Caatinga é um bioma exclusivamente brasileiro e apresenta a biodiversidade expressiva, contendo várias espécies endêmicas, e que sofrem com as variações climáticas e ações antrópicas que reduziram pela metade sua cobertura natural. A mastofauna nesta região não é bem conhecida devido à escassez de conhecimento científico fundamental, relacionado à sua taxonomia, história natural e distribuição. O bioma se distribui em sete ecoregiões e possui populações silvestres que sofrem com os impactos ambientais gerados pela fragmentação de habitat, caça e agravo dos processos de desertificação. Nesse contexto, o veado-catingueiro (Subulo gouazoubira), é o principal representante dos cervídeos neotropicais na Caatinga. A espécie que apresenta divergência recente em relação ao gênero Mazama, possui ancestrais com rápida diversificação (≅1,6 Ma) pela América do Sul. Dessa forma, o presente trabalho prospectou populações de veado-catingueiro nesta região do Nordeste, através de amostragem não invasiva, a fim de caracterizar a organização da sua genética populacional na diversidade ambiental do bioma. E desta forma, auxiliar na compreensão das distribuições das linhagens genéticas que ocorrem na Caatinga, entendendo seus perfis filogeográficos. Através de três marcadores mitocondriais (CIT B + ND2 + ND5) foram realizadas análises de genética populacional, demográficas, filogenética e filogeográficas. Os resultados demonstram que as subpopulações amostradas apresentam baixa diferenciação e que não há evidência de isolamento por distância na distribuição das linhagens, o que denota a manutenção de fluxo gênico entre elas. Uma baixa estruturação dentro de cada subpopulação e não entre elas, denota a diversidade haplotípica de cada subpopulação na demarcação filopátrica das fêmeas. Ademais, essas subpopulações detêm valores de diversidade haplotípica e nucleotídica baixas a moderadas. Análises demográficas apontam para um cenário de população em expansão, com oscilações demográficas causadas por gargalos populacionais seguidos de processos expansivos súbitos. A alta diversidade haplotípica da amostragem total é refletida numa rede de haplótipos únicos que demonstram relações genealógicas, convergindo com a hipótese dos grupamentos populacionais separados por barreiras ao fluxo gênico. Esta diversidade também está refletida na filogenia apresentada com presença de politomia entre alguns indivíduos amostrados, e são agrupados em um clado exclusivo dos demais espécimes de veado-catingueiro. Estes resultados abrem indícios para aprofundamento de estudos da possibilidade de uma Unidade Genética para a população. Além disso, apontam a necessidade de planejamento de conservação, preservando seu potencial adaptativo aliado a redução dos impactos ambientais.
The Caatinga is an exclusively Brazilian biome and has an expressive biodiversity, containing several endemic species, which suffer from climate variations and anthropic actions that have reduced its natural cover by half. The mammalian fauna in this region is not well known due to the scarcity of fundamental scientific knowledge related to its taxonomy, natural history and distribution. The biome is distributed in seven ecoregions and has wild populations that suffer from the environmental impacts generated by habitat fragmentation, hunting and worsening desertification processes. In this context, the brocket deer (Subulo gouazoubira) is the main representative of the Neotropical deer in the Caatinga. The species that presents recent divergence in relation to the genus Mazama, has ancestors with rapid diversification (≅1.6 Ma) across South America. Thus, the present work prospected populations of brown deer in this region of the Northeast, through non-invasive sampling, in order to characterize the organization of its population genetics in the environmental diversity of the biome. And in this way, help in understanding the distributions of genetic lineages that occur in the Caatinga, understanding their phylogeographic profiles. Using three mitochondrial markers (CIT B + ND2 + ND5) population genetic, demographic, phylogenetic and phylogeographic analyzes were performed. The results demonstrate that the sampled subpopulations present low differentiation and that there is no evidence of isolation by distance in the distribution of lineages, which denotes the maintenance of gene flow between them. A low structure within each subpopulation and not between them denotes the haplotypic diversity of each subpopulation in the philopatric demarcation of females. Furthermore, these subpopulations have low to moderate values of haplotypic and nucleotide diversity. Demographic analyzes point to a scenario of an expanding population, with demographic oscillations caused by population bottlenecks followed by sudden expansion processes. The high haplotypic diversity of the total sample is reflected in a network of unique haplotypes that demonstrate genealogical relationships, converging with the hypothesis of population groups separated by barriers to gene flow. This diversity is also reflected in the phylogeny presented with the presence of polytomy among some individuals sampled, and they are grouped in an exclusive clade of the other specimens of brown deer. These results open up evidence for deepening studies of the possibility of a Genetic Unit for the population. In addition, they point to the need for conservation planning, preserving its adaptive potential combined with the reduction of environmental impacts.
The Caatinga is an exclusively Brazilian biome and has an expressive biodiversity, containing several endemic species, which suffer from climate variations and anthropic actions that have reduced its natural cover by half. The mammalian fauna in this region is not well known due to the scarcity of fundamental scientific knowledge related to its taxonomy, natural history and distribution. The biome is distributed in seven ecoregions and has wild populations that suffer from the environmental impacts generated by habitat fragmentation, hunting and worsening desertification processes. In this context, the brocket deer (Subulo gouazoubira) is the main representative of the Neotropical deer in the Caatinga. The species that presents recent divergence in relation to the genus Mazama, has ancestors with rapid diversification (≅1.6 Ma) across South America. Thus, the present work prospected populations of brown deer in this region of the Northeast, through non-invasive sampling, in order to characterize the organization of its population genetics in the environmental diversity of the biome. And in this way, help in understanding the distributions of genetic lineages that occur in the Caatinga, understanding their phylogeographic profiles. Using three mitochondrial markers (CIT B + ND2 + ND5) population genetic, demographic, phylogenetic and phylogeographic analyzes were performed. The results demonstrate that the sampled subpopulations present low differentiation and that there is no evidence of isolation by distance in the distribution of lineages, which denotes the maintenance of gene flow between them. A low structure within each subpopulation and not between them denotes the haplotypic diversity of each subpopulation in the philopatric demarcation of females. Furthermore, these subpopulations have low to moderate values of haplotypic and nucleotide diversity. Demographic analyzes point to a scenario of an expanding population, with demographic oscillations caused by population bottlenecks followed by sudden expansion processes. The high haplotypic diversity of the total sample is reflected in a network of unique haplotypes that demonstrate genealogical relationships, converging with the hypothesis of population groups separated by barriers to gene flow. This diversity is also reflected in the phylogeny presented with the presence of polytomy among some individuals sampled, and they are grouped in an exclusive clade of the other specimens of brown deer. These results open up evidence for deepening studies of the possibility of a Genetic Unit for the population. In addition, they point to the need for conservation planning, preserving its adaptive potential combined with the reduction of environmental impacts.
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Florestas, Cervídeo, Caatinga, Linhagem (genética)