Relaxed phylogenies and dating with confidence
 and Aris-Brosou and Yang , present an enticing alternative to local clock models.
From these we conclude that our method is phylogenetically more accurate and precise than the traditional unrooted model while adding the ability to infer a timescale to evolution. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser. Phillips 0 1 2 Andrew Rambaut[ 0 1 2 0 Current address: Department of Computer Science, University of Auckland , Auckland , New Zealand 1 Academic Editor: David Penny, Massey University , New Zealand 2 Department of Zoology, University of Oxford , Oxford , United Kingdom In phylogenetics, the unrooted model of phylogeny and the strict molecular clock model are two extremes of a continuum.If the rate and time along each branch can only be estimated as their product, then the position of the root of the tree cannot be estimated without additional assumptions such as an outgroup or a non-reversible substitution process.This unrooted alternative to the molecular clock was first suggested by Felsenstein  and has formed the basis of all modern phylogenetic inference and is implemented in all major phylogenetic packages (e.g., PHYLIP , PAUP* , and Mr Bayes ).- From obscure beginnings, phylogenetics has become an essential tool for understanding molecular sequence variation.In the past decade, huge progress has been made in developing methods for inferring phylogenies and estimating divergence dates.