Fig. 3: Donor clades appear older than recipient clades in LGTs retained by MaxTiC.

For genuine LGTs, the donor lineage must be at least as old as the recipient. As one proxy to investigate whether this is the case for transfers retained by our MaxTiC algorithm, we calculated clade-to-tip distances (see Supplementary Information for details) for the inferred donor and recipient clades for LGTs that were retained and discarded by MaxTiC. In all three datasets, transfers retained by MaxTiC (in red) have the property that donor clades are farther from the tips of the tree than recipient clades, but the opposite pattern is observed for conflicting transfers rejected by MaxTiC (green), consistent with the idea that MaxTiC identifies genuine LGTs.