def remove_taxa(self, taxa_list):
        """
        Removes the taxa contained in taxa_list from self.sequences and
        self.species_frequency
        :param taxa_list: list, each element should be a taxon name
        """

        self.sequences = [x for x in self.sequences if x.split("|")[0]
                          not in taxa_list]

        self.species_frequency = dict((taxon, val) for taxon, val in
                                      self.species_frequency.items()
                                      if taxon not in taxa_list)