Figure 2

Mutagenetic trees mixture model with two components. Timed mutagenetic trees mixture model estimated on the HIV dataset. The responsibility of the nontrivial tree component is 0.82. A sample is generated from the noise component with probability 0.18. The nodes represent the genetic events and the labels of the edges depicted with dark blue color are the conditional probabilities between the events. The nontrivial branching of the mixture model shows the two typical pathways 70 – 219 and 215 – 41 that develop under zidovudine monotherapy. Exponential distributions are assumed for the time difference between the occurrences of the child and parent events on all edges and for the sampling time (with mean sampling time equal to 1). The timed model then is obtained by mapping the edges with the expected waiting times of occurrence of the child events (red color), given that the parent events has occurred. The GPS of the pattern x, which specifies the occurrence of the subset of events {0, 70R, 219E/Q, 67N}, is calculated using the timed mutagenetic trees mixture model and formula (1).