Balanço híbrido e desempenho locomotor em esécies de anuros de mata atlântica e cerrado
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Data
2010-05-05
Autores
Titon Junior, Braz [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Como anfíbios em geral perdem água por evaporação a taxas equivalentes à de uma superfície de água livre, a disponibilidade de água no ambiente é de fundamental importância para determinar os limites da distribuição das espécies deste grupo, bem como a evolução de caracteres fisiológicos associados ao balanço hídrico. No Estado de São Paulo, a comparação entre espécies de anuros características da Floresta Atlântica e do Cerrado representa um interessante sistema para o estudo das relações entre o balanço hídrico e a distribuição geográfica de anuros, já que estes dois biomas diferem em aspectos fundamentais para a biologia deste grupo, tais como regime de chuvas e cobertura vegetal. O objetivo deste projeto foi investigar a evolução da sensibilidade do desempenho locomotor à desidratação (SDLD), taxas de perda de água por evaporação (TPAE), resistência à perda de água por evaporação (RPAE) e taxas de reidratação a partir de água livre (TRAL) ao longo da filogenia de anuros do Estado de São Paulo, bem como investigar as relações evolutivas entre estas variáveis e suas possíveis associações com a distribuição geográfica das espécies, através de uma abordagem comparativa entre anuros de Mata Atlântica e Cerrado. Foi encontrada presença de sinal filogenético para RPAE, TPAE e a massa corpórea, havendo para estas, provavelmente, uma grande influência da evolução por deriva genética ao longo da filogenia. As relações entre todas as variáveis corrigidas para a filogenia podem ser resumidas por dois componentes principais. O primeiro componente explica 49,77% da variância entre as espécies e mostra uma relação positiva entre as TPAE e a SDLD e ambas se relacionando negativamente com a RPAE. Uma vez que a variação na resistência da pele à perda de água por evaporação é determinante da taxa de perda de água por...
Amphibians are generally characterized by rates of evaporative water loss equivalent to those observed for a free water surface. In this way, water availability in the environment should be fundamental to determine the limits of geographical distribution and the evolution of physiological characters associated with anuran water balance. The comparison of anuran species from the Atlantic Forest and the Cerrado in the State of São Paulo consists an interesting system to study the relationship between water balance and geographic distribution, since these two biomes differ in fundamental aspects for amphibian life history, such as rainfall and vegetation cover. The objective of this project was to investigate (1) the evolution of the sensitivity of locomotor performance to dehydration (SDLD), rates of evaporative water loss (TPAE), resistance to evaporative water loss (RPAE) and rates of rehydration from free water (TRAL) along the phylogeny of anurans from the State of São Paulo, (2) the evolutionary relationships between these variables, and (3) their possible associations with the geographic distribution of the species, through a comparative approach of species found in the Atlantic Forest and the Cerrado. We found significant phylogenetic signal for RPAE, TPAE, and body mass, probably with a large influence of genetic drift along the phylogeny in the evolution of these characters. The relationships between all variables corrected for phylogeny can be summarized by two main components. The first component explained 49.77% of the variance, and showed a positive relationship between TPAE and SDLD, and both were negatively related to RPAE. Since the variation in the rate of evaporative water loss is determined by skin resistance to evaporative water loss, TPAE and RPAE should comprise an evolutionary unit. A plausible hypothesis for the negative relationship between TPAE and SDLD is ...(Complete abstract click electronic access below)
Amphibians are generally characterized by rates of evaporative water loss equivalent to those observed for a free water surface. In this way, water availability in the environment should be fundamental to determine the limits of geographical distribution and the evolution of physiological characters associated with anuran water balance. The comparison of anuran species from the Atlantic Forest and the Cerrado in the State of São Paulo consists an interesting system to study the relationship between water balance and geographic distribution, since these two biomes differ in fundamental aspects for amphibian life history, such as rainfall and vegetation cover. The objective of this project was to investigate (1) the evolution of the sensitivity of locomotor performance to dehydration (SDLD), rates of evaporative water loss (TPAE), resistance to evaporative water loss (RPAE) and rates of rehydration from free water (TRAL) along the phylogeny of anurans from the State of São Paulo, (2) the evolutionary relationships between these variables, and (3) their possible associations with the geographic distribution of the species, through a comparative approach of species found in the Atlantic Forest and the Cerrado. We found significant phylogenetic signal for RPAE, TPAE, and body mass, probably with a large influence of genetic drift along the phylogeny in the evolution of these characters. The relationships between all variables corrected for phylogeny can be summarized by two main components. The first component explained 49.77% of the variance, and showed a positive relationship between TPAE and SDLD, and both were negatively related to RPAE. Since the variation in the rate of evaporative water loss is determined by skin resistance to evaporative water loss, TPAE and RPAE should comprise an evolutionary unit. A plausible hypothesis for the negative relationship between TPAE and SDLD is ...(Complete abstract click electronic access below)
Descrição
Palavras-chave
Mata Atlântica, Cerrados, Anuro, Balanço hidrológico
Como citar
TITON JUNIOR, Braz. Balanço híbrido e desempenho locomotor em esécies de anuros de mata atlântica e cerrado. 2010. 56 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2010.