def mslike(pop, **kwargs):
    """
    Function to establish default parameters
    for a single-locus simulation for standard pop-gen
    modeling scenarios.

    :params pop: An instance of :class:`fwdpy11.DiploidPopulation`
    :params kwargs: Keyword arguments.
    """
    import fwdpy11
    if isinstance(pop, fwdpy11.DiploidPopulation) is False:
        raise ValueError('incorrect pop type: ' + str(type(pop)))
    defaults = {'simlen': 10 * pop.N, 'beg': 0.0, 'end': 1.0, 'theta': 
        100.0, 'pneutral': 1.0, 'rho': 100.0, 'dfe': None}
    for key, value in kwargs.items():
        if key in defaults:
            defaults[key] = value
    import numpy as np
    params = {'demography': np.array([pop.N] * defaults['simlen'], dtype=np
        .uint32), 'nregions': [fwdpy11.Region(defaults['beg'], defaults[
        'end'], 1.0)], 'recregions': [fwdpy11.Region(defaults['beg'],
        defaults['end'], 1.0)], 'rates': (defaults['pneutral'] * defaults[
        'theta'] / (4.0 * pop.N), (1.0 - defaults['pneutral']) * defaults[
        'theta'] / (4.0 * pop.N), defaults['rho'] / (4.0 * float(pop.N))),
        'gvalue': fwdpy11.Multiplicative(2.0)}
    if defaults['dfe'] is None:
        params['sregions'] = []
    else:
        params['sregions'] = [defaults['dfe']]
    return params
