The starting population is constructed from randomly selected amines from a 250K molecule subset of the ZINC database . The entries in the database are all commercially-available compounds, which makes it ideal for virtual screening. From these molecule we extract moieties that were connected to non-ring Nitrogen atoms by single bonds. The single bond to nitrogen is broken and replaced by a dummy atom, which is used to indicate the attachment point of the ligand. 50-100 ligands (depending on population size) are then selected at random to form the initial population.