Unidentifiable divergence times in rates-across-sites models

Details Unidentifiable divergence times in rates-across-sites models Unidentifiable divergence times in rates-across-sites models

2004-08-15

arxiv.org/abs/q-bio/0408011v2

Biology

Quantitative Biology

Populations and Evolution

13 pages, update to include referee's comments, to appear in IEEE/ACM Transactions on Computational Biology and Bioinformatics

Scientific paper

The rates-across-sites assumption in phylogenetic inference posits that the rate matrix governing the Markovian evolution of a character on an edge of the putative phylogenetic tree is the product of a character-specific scale factor and a rate matrix that is particular to that edge. Thus, evolution follows basically the same process for all characters, except that it occurs faster for some characters than others. To allow estimation of tree topologies and edge lengths for such models, it is commonly assumed that the scale factors are not arbitrary unknown constants, but rather unobserved, independent, identically distributed draws from a member of some parametric family of distributions. A popular choice is the gamma family. We consider an example of a clock-like tree with three taxa, one unknown edge length, and a parametric family of scale factor distributions that contain the gamma family. This model has the property that, for a generic choice of unknown edge length and scale factor distribution, there is another edge length and scale factor distribution which generates data with exactly the same distribution, so that even with infinitely many data it will be typically impossible to make correct inferences about the unknown edge length.

Affiliated with

Also associated with

No associations

Rating

Unidentifiable divergence times in rates-across-sites models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Unidentifiable divergence times in rates-across-sites models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Unidentifiable divergence times in rates-across-sites models will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-580224