|A multi-locus time-calibrated phylogeny of the brown algae (Heterokonta, Ochrophyta, Phaeophyceae): Investigating the evolutionary nature of the ‘‘brown algal crown radiation”|Silberfeld, T.; Leigh, J. W.; Verbruggen, H.; Cruaud, C.; de Reviers, B.; Rousseau, F. (2010). 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): 659-674. dx.doi.org/10.1016/j.ympev.2010.04.020
In: Molecular Phylogenetics and Evolution. Elsevier: Orlando, FL. ISSN 1055-7903; e-ISSN 1095-9513
Phaeophyceae; Brown algal crown radiation; Multi-marker phylogeny; Time-calibrated phylogeny; Bayesian relaxed molecular clock; Hard; soft polytomy; Non-molecular characters evolution
|Auteurs|| || Top |
- Silberfeld, T.
- Leigh, J. W.
- Verbruggen, H.
- Cruaud, C.
- de Reviers, B.
- Rousseau, F.
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.