Data/hora: 02/06/2024 08:56:47

Provedor de dados: 	74	
País: 	Brazil	
Título: 	Diversification of Ramphastinae (Aves, Ramphastidae) prior to the Cretaceous/Tertiary boundary as shown by molecular clock of mtDNA sequences	
Autores: 	Nahum,Laila Alves; Pereira,Sérgio Luiz; Campos Fernandes,Flora Maria de; Russo Matioli,Sergio; Wajntal,Anita.	
Data: 	2003-12-01	
Ano: 	2003	
Palavras-chave: 	Divergence times; K/T; Mass extinction; Cytochrome b; 12S rDNA; Paleogeography; Phylogeny.	
Resumo: 	Partial cytochrome b and 12S rDNA mitochondrial DNA sequences of eight representatives of the Ramphastidae family were analyzed. We applied the linearized tree method to identify sequences evolving at similar rates and estimated the divergence times among some of the taxa analyzed. After excluding Ramphastos tucanus and Capito dayi from our data set, the remaining taxa presented a constant rate of DNA substitution, and branch lengths could be re-estimated with a clock constraint using the maximum likelihood method. Branch lengths were calibrated assuming that Galliformes and Piciformes split around 100 million years ago (mya). Our results indicate that Ramphastinae, and probably Capitoninae, diverged from other Piciformes in the Late Cretaceous (~82 mya), suggesting that Piciformes is another avian order that survived the mass extinction event occurred 65 mya at the Cretaceous/Tertiary (K/T) boundary. The divergence times estimated within the Ramphastinae genera cover the period from the Middle Eocene (around 47 mya) through the Late Miocene (9.5 mya). Our estimate of divergence time is coincidental with the split of the African and the South American continents and other intense geologic activities and modifications of the areas which correspond to the current Neotropics. These events might have influenced the diversification of Ramphastinae in South America.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000400003	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S1415-47572003000400003	
Formato: 	text/html	
Fonte: 	Genetics and Molecular Biology  v.26 n.4 2003	
Fonte: 	info:eu-repo/semantics/openAccess