A multi-locus time-calibrated phylogeny of the brown algae (Heterokonta, Ochrophyta, Phaeophyceae): Investigating the evolutionary nature of the "brown algal crown radiation".
Mol Phylogenet Evol
; 56(2): 659-74, 2010 Aug.
Article
en En
| MEDLINE
| ID: mdl-20412862
The most conspicuous feature in previous phaeophycean phylogenies is a large polytomy known as the brown algal crown radiation (BACR). The BACR encompasses 10 out of the 17 currently recognized brown algal orders. A recent study has been able to resolve a few nodes of the BACR, suggesting that it may be a soft polytomy caused by a lack of signal in molecular markers. The present work aims to refine relationships within the BACR and investigate the nature and timeframe of the diversification in question using a dual approach. A multi-marker phylogeny of the brown algae was built from 10 mitochondrial, plastid and nuclear loci (>10,000 nt) of 72 phaeophycean taxa, resulting in trees with well-resolved inter-ordinal relationships within the BACR. Using Bayesian relaxed molecular clock analysis, it is shown that the BACR is likely to represent a gradual diversification spanning most of the Lower Cretaceous rather than a sudden radiation. Non-molecular characters classically used in ordinal delimitation were mapped on the molecular topology to study their evolutionary history.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Filogenia
/
Evolución Molecular
/
Phaeophyceae
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Phylogenet Evol
Asunto de la revista:
BIOLOGIA
/
BIOLOGIA MOLECULAR
Año:
2010
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos