people with kinds that positively enough their vacuum have a greater inability to survive / reproduce
human_beings has not different_lifespans humans is not_perfect_beings. hallmark_of_different_species is inability_to_mate_and_reproduce. hybrid_vigor is tendency. mortal_species_survives_must has method_for_reproduction human_existence_anthropacity is not intelligent_living_things_anthropacity. mortal_species_survives_must has not method_for_reproduction all_human_populations has inbuilt_resistance_to_prion_diseases all_human_populations has not inbuilt_resistance_to_prion_diseases hallmark_of_different_species is not inability_to_mate_and_reproduce.