docs: def   define_zip_index_for_species(names_ppn_world,
                                     number_names_ppn_world):
      ''' This just give back cl, that is the original index as it is read from files from a data file.'''
  
      #connect the specie number in the list, with the specie name
      global cl
      cl={}
      for a,b in zip(names_ppn_world,number_names_ppn_world):
          cl[a] = b