def isRetrovirus(lineage):
    """
    Determine whether a lineage corresponds to a retrovirus.

    @param lineage: An iterable of C{LineageElement} instances.
    @return: C{True} if the lineage corresponds to a retrovirus, C{False}
        otherwise.
    """
    for element in lineage:
        if element.rank == 'family' and element.name == 'Retroviridae':
            return True

    return False