Patterns of Insertions and Their Covariation With Substitutions in the Rat, Mouse, and Human Genomes

Phylogenetic tree for rat, mouse, and human and their last common ancestors. The last common ancestor for human, mouse, and rat is A_HMR, and the last common ancestor for mouse and rat is A_MR; A_HMR and the ancestors to other eutherian mammalian orders diverged earlier from the last common eutherian ancestor A_eu. The branch from A_HMR to human is defined as “human” and is referred to by the suffix “H”, the branch from A_HMR to A_MR is defined as “rodent” and is referred to by the suffix “Ro”, the branch from A_MR to rat is defined as “rat” and is referred to by the suffix “R”, and the branch from A_MR to mouse is defined as “mouse” and is referred to by the suffix “M”. Average approximate times for the divergence from A_HMR and A_MR (Adkins et al. 2001; Mouse Genome Sequencing Consortium 2002; Springer et al. 2003) are given in millions of years.