Migration

Constant migration

By default, slime assumes that the admixed populations is created by a single pulse of migration from the reference populations. This can be changed by specifying migration rates from each reference population using the add_migration_rate method:

>>> config = slime.PopulationConfiguration(initial_size=100)

>>> script = slime.RecentHistory(final_gen=20, chrom_length=10,
...         recombination=.01, reference_configs=[config, config],
...         adm_configs=config, prop=[0.3,0.7])
>>> script.add_migration_rate(rates=[.01,.02])

To change migration rates at a particular time in the simulation, use the optional argument time. For example, adding this line to the above code will stop all migration into the admixed population at the end of the 5th generation:

>>> script.add_migration_rate(rates=[0, 0], time=(5, 'late'))

Mass migration

You can also add one-off migrations into the admixed population using the add_mass_migration method.

>>> script.add_mass_migration(prop=[.1, .1], time=(9, 'late'))

Note

At the moment, the add_mass_migration method will set migration rates in the following generation to 0 (not to what they were in earlier generations of the simulation). You can set migration rates in generation n+1 to what they were before using add_migration_rate.