Fig. 2. Sheep relative to human and livestock evolution.
A phylogenetic tree generated using single-copy orthologous genes (10). The origins (black) and amplifications (red) of genes discussed in the text are marked. The scale is in millions of years ago (Mya). Blue numbers on the nodes are the divergence time from present (Mya) and its confidence interval. Dates for major events in the evolution of grasses are from (4) and (5).