Relaxed phylogenies and dating with confidence

Such problems with the molecular clock hypothesis have resulted in it being abandoned almost entirely for phylogenetic inference in favor of a model that assumes that every branch has an independent rate of molecular evolution.Under such an assumption, it is possible to infer phylogenies (e.g., [9,10]), but not to estimate molecular rates or divergence times, because the individual contributions of rate and time to molecular evolution cannot be separated.

relaxed phylogenies and dating with confidence-36

These models open the gate to a new field of “relaxed phylogenetics.” Here we introduce a new approach to performing relaxed phylogenetic analysis.We find no significant rate autocorrelation among branches in three large datasets, suggesting that autocorrelated models are not necessarily suitable for these data.In addition, we place these datasets on the continuum of clocklikeness between a strict molecular clock and the alternative unrooted extreme.In phylogenetics, the unrooted model of phylogeny and the strict molecular clock model are two extremes of a continuum.Despite their dominance in phylogenetic inference, it is evident that both are biologically unrealistic and that the real evolutionary process lies between these two extremes.

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