Fig. 2

Evolution of GH9 domain. A Bayesian inference (BI) dated tree was estimated (maximum clade credibility) from the computed tree population (n = 4476; burn − in = 70%) using the WAG amino acid substitution model and parent of the clade of bacteria as the root. Whilst, node ages (= node height = branch time of the longest diverging taxa) and branch times are in Mya, support for branch points are indicated by the posterior probabilities (PP%) and bootstrap values (n = 1000; ML%), i.e., support = PP % , ML%. The root for this tree was the parent of bacteria (3170 − 4180 Mya).The log likelihood for this tree was (≈ − 0.0838233). Abbreviations: BI, Bayesian inference; GH9, glycoside hydrolase; Mya, millions of years; WAG, Whelan and Goldman