Fig. 4From: Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practiceThe time to most recent common ancestor (TMRCA) of the archetypal MRSA isolates under various combinations of clock and population model in BEAST. Plots showing mean (dots) TMRCA and 95% highest posterior density for the TMRCA are indicated. The dates of introduction of penicillin and methicillin into clinical use in the UK are indicated with green and red lines, respectivelyBack to article page