Data/hora: 07/06/2024 00:36:07

Provedor de dados: | 94
País: | Brazil
Título: | Annonaceae substitution rates: a codon model perspective
Autores: | Chatrou,Lars Willem; Pirie,Michael David; Velzen,Robin Van; Bakker,Freek Theodoor.
Data: | 2014-01-01
Ano: | 2014
Palavras-chave: | Annonaceae; Branch lengths; Codon models; Non-synonymous substitution rate; Phylogenetics; Synonymous substitution rate.
Resumo: | The Annonaceae includes cultivated species of economic interest and represents an important source of information for better understanding the evolution of tropical rainforests. In phylogenetic analyses of DNA sequence data that are used to address evolutionary questions, it is imperative to use appropriate statistical models. Annonaceae are cases in point: Two sister clades, the subfamilies Annonoideae and Malmeoideae, contain the majority of Annonaceae species diversity. The Annonoideae generally show a greater degree of sequence divergence compared to the Malmeoideae, resulting in stark differences in branch lengths in phylogenetic trees. Uncertainty in how to interpret and analyse these differences has led to inconsistent results when estimating the ages of clades in Annonaceae using molecular dating techniques. We ask whether these differences may be attributed to inappropriate modelling assumptions in the phylogenetic analyses. Specifically, we test for (clade-specific) differences in rates of non-synonymous and synonymous substitutions. A high ratio of nonsynonymous to synonymous substitutions may lead to similarity of DNA sequences due to convergence instead of common ancestry, and as a result confound phylogenetic analyses. We use a dataset of three chloroplast genes (rbcL, matK, ndhF) for 129 species representative of the family. We find that differences in branch lengths between major clades are not attributable to different rates of non-synonymous and synonymous substitutions. The differences in evolutionary rate between the major clades of Annonaceae pose a challenge for current molecular dating techniques that should be seen as a warning for the interpretation of such results in other organisms.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452014000500013
Editor: | Sociedade Brasileira de Fruticultura
Relação: | 10.1590/S0100-29452014000500013
Formato: | text/html
Fonte: | Revista Brasileira de Fruticultura  v.36 n.spe1 2014
Fonte: | info:eu-repo/semantics/openAccess