Fig. 2

a The calibrated Mollicute phylogeny and putative LGT events. Uni-directional LGTs are depicted by → (coloured in blue), while ⇔ (coloured in red) represents the bi-directional exchange of genes between lineages. Edge numbers are used in panels b and c. Both → and ⇔ represents all the LGTs events that appeared on average 50 % or more, in MAP trees. b Histogram of gene families where 〈From, To 〉 edges appeared on average 50 % or more in MAP trees; X-axis represents 〈From, To 〉 edges. c Histogram of gene families where 〈From, To 〉 edges appeared on average 50 % or more in the sampled trees