MRCAPrior does not need to traverse tree if only root is used #424
MRCAPrior does not need to traverse tree if only root is used #424

CompEvol/beast2,Anaphory/beast2,tgvaughan/beast2,CompEvol/beast2,Anaphory/beast2,CompEvol/beast2,CompEvol/beast2,tgvaughan/beast2,tgvaughan/beast2,tgvaughan/beast2,Anaphory/beast2,Anaphory/beast2