2.8 | Species divergence time estimation
Single-copy gene families among Pse. libanotica , A. tauschii , B. distachyon , T. aestivum , T. durum ,T. dicoccoides, T. urartu , H. vulgare , O. sativa , S. cereale , Sorghum bicolor , Z. mays ,Dactylis glomerata and Arabidopsis thaliana were selected using the MCMCTree program (http://abacus.gene.ucl.ac.uk/software/paml.html) in Phylogenetic Analysis with Maximum Likelihood (PAML) for an estimate the divergence time of the nodes on the phylogenetic tree. The MCMCTree parameters were as follows: a burn-in of 10,000 steps, sample number of 100,000, and sample frequency of 2. The calibration times of divergence were obtained from the TimeTree database (http://www.timetree.org/): 2.20–3.80 Mya for T. durum and T. aestivum , 3.60–4.40 Mya for T. dicoccoides and T. urartu , 10.0–11.40 Mya forPse. libanotica and A. tauschii , 9.60–11.90 Mya forS . cereale and H. vulgare , 31.4–47.2 Mya forDactylis glomerata and B. distachyon , 9. 0–12.0 Mya forS. bicolor and Z. mays , 47.2–189 Mya for O. sativaand A. thaliana .