PHASE_NN1 ONE_CRD :_PUN APRIL_NP0 1953_CRD 
James_NP0 Watson_NP0 and_CJC Francis_NP0 Crick_NP0 published_VVD their_DPS description_NN1 of_PRF the_AT0 structure_NN1 of_PRF DNA_NN1 in_PRP Nature_NN1 on_PRP 25_CRD April_NP0 1953._CRD Their_DPS paper_NN1 included_VVD a_AT0 drawing_NN1 of_PRF the_AT0 molecule_NN1 ,_PUN complete_AJ0 with_PRP the_AT0 sugar-phosphate_AJ0 chains_NN2 of_PRF the_AT0 double_AJ0 helix_NN1 and_CJC the_AT0 base_NN1 pairs_NN2 that_CJT connect_VVB the_AT0 two_CRD chains_NN2 ._SENT 
The_AT0 artist_NN1 who_PNQ created_VVD the_AT0 drawing_NN1 was_VBD Odile_NP0 Crick_NP0 ,_PUN wife_NN1 of_PRF Francis_NP0 ._SENT In_PRP the_AT0 words_NN2 of_PRF James_NP0 Watson_NP0 ,_PUN "_PUQ Francis_NP0 ca_VM0 n't_XX0 draw_VVI ,_PUN and_CJC I_PNP ca_VM0 n't_XX0 draw_VVI ,_PUN and_CJC we_PNP needed_VVD something_PNI done_VDN quick_AV0 ..._PUN ._SENT [_PUL The_AT0 drawing_NN1 ]_PUR showed_VVD the_AT0 essence_NN1 of_PRF the_AT0 structure_NN1 "_PUQ ._SENT 
There_EX0 is_VBZ something_PNI distinctive_AJ0 about_PRP that_DT0 drawing_NN1 :_PUN DNA_NN1 has_VHZ a_AT0 vertical_AJ0 line_NN1 running_VVG up_AVP the_AT0 center_NN1 of_PRF its_DPS structure_NN1 ._SENT Why_AVQ ?_SENT I_PNP suggest_VVB two_CRD possible_AJ0 reasons_NN2 ._SENT The_AT0 first_ORD I_PNP derive_VVB from_PRP a_AT0 famous_AJ0 photo_NN1 taken_VVN on_PRP 21_CRD May_NP0 1953._CRD It_PNP shows_VVZ Watson_NP0 and_CJC Crick_NP0 observing_VVG their_DPS three-dimensional_AJ0 metal_NN1 model_NN1 of_PRF DNA_NN1 ._SENT In_PRP the_AT0 photo_NN1 there_EX0 is_VBZ a_AT0 vertical_AJ0 rod_NN1 running_VVG up_AVP the_AT0 center_NN1 of_PRF the_AT0 model_NN1 ._SENT The_AT0 3D_NN0 model_NN1 could_VM0 not_XX0 support_VVI itself_PNX with_PRP the_AT0 parts_NN2 that_CJT represented_VVD the_AT0 sugar-phosphate_AJ0 double_AJ0 helix_NN1 ._SENT The_AT0 four_CRD bases_NN2 of_PRF the_AT0 model_NN1 are_VBB clamped_VVN horizontally_AV0 to_PRP the_AT0 vertical_AJ0 rod_NN1 ,_PUN and_CJC the_AT0 two_CRD sides_NN2 of_PRF the_AT0 double_AJ0 helix_NN1 are_VBB attached_VVN to_PRP the_AT0 bases_NN2 ._SENT 
This_DT0 is_VBZ ironic_AJ0 ._SENT Ordinarily_AV0 the_AT0 double_AJ0 helix_NN1 is_VBZ supposed_AJ0 to_TO0 be_VBI the_AT0 stable_AJ0 structure_NN1 :_PUN It_PNP consists_VVZ of_PRF strongly_AV0 bonded_AJ0 sugars_NN2 ,_PUN phosphates_NN2 and_CJC bases_NN2 ,_PUN whereas_CJS the_AT0 base_NN1 pairs_NN2 are_VBB the_AT0 more_AV0 unstable_AJ0 part_NN1 in_PRP the_AT0 sense_NN1 that_CJT they_PNP break_VVB when_AVQ the_AT0 molecule_NN1 comes_VVZ apart_AV0 to_TO0 generate_VVI RNA_NN1 and_CJC when_CJS it_PNP is_VBZ reproduced_VVN in_PRP polymerase_NN1 chain_NN1 reaction_NN1 ._SENT Mutations_NN2 arise_VVB when_CJS insertion_NN1 ,_PUN deletion_NN1 or_CJC substitution_NN1 disrupts_VVZ the_AT0 sequence_NN1 of_PRF bases_NN2 ._SENT It_PNP is_VBZ rare_AJ0 for_PRP this_DT0 to_TO0 happen_VVI when_CJS the_AT0 double_AJ0 helix_NN1 is_VBZ intact_AJ0 ._SENT 
The_AT0 three-dimensional_AJ0 model_NN1 is_VBZ older_AJC than_CJS the_AT0 photo_NN1 ,_PUN so_CJS it_PNP might_VM0 be_VBI the_AT0 basis_NN1 for_PRP Odile_NP0 Crick_NP0 's_POS drawing_NN1 ._SENT 
There_EX0 is_VBZ another_DT0 possible_AJ0 antecedent_AJ0 for_PRP the_AT0 vertical_AJ0 line_NN1 ._SENT On_PRP 15_CRD March_NP0 1953_CRD ,_PUN Crick_NP0 wrote_VVD to_PRP his_DPS son_NN1 about_PRP what_DTQ he_PNP and_CJC Watson_NP0 had_VHD discovered_VVN ._SENT The_AT0 letter_NN1 includes_VVZ a_AT0 rough_AJ0 sketch_NN1 of_PRF DNA_NN1 ,_PUN including_PRP the_AT0 double_AJ0 helix_NN1 and_CJC the_AT0 base_NN1 pairs_NN2 ._SENT This_DT0 sketch_NN1 has_VHZ a_AT0 vertical_AJ0 line_NN1 running_VVG up_AVP the_AT0 center_NN1 of_PRF the_AT0 molecule_NN1 ._SENT Imagine_VVB that_CJT Odile_NP0 Crick_NP0 's_POS professional_AJ0 drawing_NN1 was_VBD a_AT0 refined_AJ0 version_NN1 of_PRF Francis_NP0 Crick_NP0 's_POS sketch_NN1 ._SENT 
Odile_NP0 Crick_NP0 's_POS drawing_NN1 seems_VVZ to_TO0 be_VBI either_AV0 an_AT0 artifact_NN1 of_PRF the_AT0 rod_NN1 supporting_VVG the_AT0 three-dimensional_AJ0 model_NN1 or_CJC an_AT0 improved_AJ0 version_NN1 of_PRF Francis_NP0 Crick_NP0 's_POS sketch_NN1 ._SENT 
After_CJS I_PNP made_VVD the_AT0 point_NN1 about_PRP the_AT0 vertical_AJ0 line_NN1 in_PRP the_AT0 1953_CRD drawing_NN1 on_PRP Brigitte_NP0 Nerlich_NP0 's_POS blog_NN1 ,_PUN this_DT0 comment_NN1 came_VVD from_PRP Kindra_NP0 Crick_NP0 ,_PUN granddaughter_NN1 of_PRF Francis_NP0 Crick_NP0 :_PUN "_PUQ Interesting_AJ0 interpretation_NN1 ._SENT I_PNP believe_VVB the_AT0 central_AJ0 line_NN1 was_VBD intended_VVN to_TO0 call_VVI attention_NN1 to_PRP the_AT0 three_CRD dimensional_AJ0 shape_NN1 ._SENT A_AT0 reference_NN1 line_NN1 similar_AJ0 to_PRP the_AT0 arrows_NN2 which_DTQ very_AV0 simply_AV0 indicate_VVB that_CJT the_AT0 [_PUL strands_NN2 ]_PUR run_VVN in_PRP opposite_AJ0 directions_NN2 "_PUQ ._SENT Commenting_VVG on_PRP the_AT0 blog_NN1 ,_PUN Peter_NP0 Ellis_NP0 added_VVD :_PUN "_PUQ There_EX0 's_VBZ no_AT0 mystery_NN1 here_AV0 ._SENT In_PRP the_AT0 caption_NN1 of_PRF the_AT0 figure_NN1 in_PRP the_AT0 original_AJ0 paper_NN1 ,_PUN it_PNP states_VVZ ,_PUN '_PUQ The_AT0 vertical_AJ0 line_NN1 marks_VVZ the_AT0 fibre_NN1 axis_NN1 ._SENT '_PUQ ..._PUN the_AT0 line_NN1 does_VDZ not_XX0 represent_VVI anything_PNI physical_AJ0 and_CJC is_VBZ simply_AV0 a_AT0 guide_NN1 to_PRP the_AT0 underlying_AJ0 symmetry_NN1 "_PUQ ._SENT 
The_AT0 caption_NN1 says_VVZ ,_PUN "_PUQ This_DT0 figure_NN1 is_VBZ purely_AV0 diagrammatic_AJ0 "_PUQ ._SENT And_CJC then_AV0 ,_PUN "_PUQ The_AT0 two_CRD ribbons_NN2 symbolize_VVB the_AT0 two_CRD phosphatesugar_AJ0 chains_NN2 ,_PUN and_CJC the_AT0 horizontal_AJ0 rods_NN2 [_PUL symbolize_VVB ]_PUR the_AT0 pairs_NN2 of_PRF bases_NN2 holding_VVG the_AT0 chains_NN2 together_AV0 "_PUQ ._SENT If_CJS "_PUQ purely_AV0 diagrammatic_AJ0 "_PUQ means_VVZ nonrepresentational_AJ0 ,_PUN then_AV0 the_AT0 ribbons_NN2 and_CJC the_AT0 rods_NN2 are_VBB representational_AJ0 ,_PUN and_CJC the_AT0 reader_NN1 could_VM0 infer_VVI that_CJT the_AT0 line_NN1 is_VBZ just_AV0 as_AV0 representational_AJ0 as_CJS the_AT0 ribbons_NN2 and_CJC the_AT0 rods_NN2 ._SENT 
And_CJC there_EX0 is_VBZ a_AT0 problem_NN1 with_PRP the_AT0 "_PUQ underlying_AJ0 symmetry_NN1 "_PUQ :_PUN The_AT0 base_NN1 pairs_NN2 are_VBB symmetrical_AJ0 one_CRD way_NN1 and_CJC asymmetrical_AJ0 another_DT0 way_NN1 ._SENT Adenine_NN1 is_VBZ wider_AJC than_CJS thymine_NN1 ,_PUN and_CJC guanine_NN1 is_VBZ wider_AJC than_CJS cytosine_NN1 ._SENT All_DT0 four_CRD base_NN1 pairs_NN2 have_VHB the_AT0 same_DT0 total_AJ0 width_NN1 ,_PUN namely_AV0 ,_PUN 2.0_CRD nanometers_NN2 (_PUL which_DTQ Watson_NP0 and_CJC Crick_NP0 described_VVD as_PRP 20.0_CRD Ǻ_NP0 )_PUR ,_PUN so_CJS the_AT0 DNA_NN1 molecule_NN1 is_VBZ externally_AV0 symmetrical_AJ0 ._SENT But_CJC the_AT0 hydrogen_NN1 bonds_NN2 connecting_VVG each_DT0 pair_NN0 of_PRF bases_NN2 are_VBB off-center_AJ0 ._SENT 
Anyone_PNI can_VM0 imagine_VVI whatever_DTQ internal_AJ0 symmetry_NN1 they_PNP want_VVB to_TO0 ,_PUN but_CJC it_PNP seems_VVZ to_PRP me_PNP misleading_AJ0 to_TO0 depict_VVI the_AT0 internal_AJ0 symmetry_NN1 of_PRF a_AT0 molecule_NN1 that_DT0 is_VBZ internally_AV0 asymmetrical_AJ0 ._SENT The_AT0 vertical_AJ0 line_NN1 represents_VVZ a_AT0 nonexistent_AJ0 symmetry_NN1 ._SENT 
This_DT0 raises_VVZ another_DT0 point_NN1 ._SENT The_AT0 model_NN1 ,_PUN the_AT0 sketch_NN1 and_CJC the_AT0 drawing_NN1 all_DT0 depict_VVB DNA_NN1 as_PRP a_AT0 vertical_AJ0 object_NN1 ._SENT But_CJC DNA_NN1 itself_PNX can_VM0 be_VBI vertical_AJ0 ,_PUN horizontal_AJ0 or_CJC diagonal_AJ0 within_PRP a_AT0 genome_NN1 ._SENT I_PNP conclude_VVB that_CJT it_PNP is_VBZ an_AT0 aesthetic_AJ0 convention_NN1 ,_PUN not_XX0 an_AT0 empirical_AJ0 conclusion_NN1 ,_PUN to_TO0 depict_VVI DNA_NN1 as_CJS vertical_AJ0 ._SENT Indeed_AV0 ,_PUN the_AT0 recent_AJ0 illustrated_AJ0 edition_NN1 of_PRF Watson_NP0 's_VBZ The_AT0 Double_AJ0 Helix_NN1 shows_VVZ DNA_NN1 horizontally_AV0 on_PRP the_AT0 dust_NN1 jacket_NN1 ._SENT 
This_DT0 reminds_VVZ us_PNP that_CJT it_PNP is_VBZ often_AV0 difficult_AJ0 to_TO0 depict_VVI a_AT0 natural_AJ0 object_NN1 in_PRP models_NN2 and_CJC drawings_NN2 ._SENT This_DT0 can_VM0 be_VBI especially_AV0 problematic_AJ0 for_PRP nanoscale_NN1 objects_NN2 ,_PUN e.g._AV0 molecules_NN2 ,_PUN because_CJS they_PNP cannot_VVB be_VBI seen_VVN with_PRP optical_AJ0 microscopes_NN2 ._SENT As_CJS best_AV0 as_CJS I_PNP can_VM0 tell_VVI ,_PUN the_AT0 vertical_AJ0 line_NN1 disappeared_VVN from_PRP illustrations_NN2 of_PRF DNA_NN1 not_XX0 long_AV0 after_PRP the_AT0 paper_NN1 of_PRF 25_CRD April_NP0 1953._CRD It_PNP still_AV0 appears_VVZ in_PRP some_DT0 three-dimensional_AJ0 models_NN2 because_CJS those_DT0 models_NN2 need_VVB a_AT0 vertical_AJ0 rod_NN1 to_TO0 support_VVI them_PNP ._SENT Yet_AV0 if_CJS a_AT0 two-dimensional_AJ0 depiction_NN1 of_PRF DNA_NN1 included_VVD it_PNP today_AV0 ,_PUN implying_VVG that_CJT it_PNP was_VBD representational_AJ0 ,_PUN then_AV0 scientists_NN2 would_VM0 object_VVI that_CJT DNA_NN1 includes_VVZ no_AT0 such_DT0 thing_NN1 ._SENT 
PHASE_NN1 TWO_CRD :_PUN THE_AT0 GOLDEN_AJ0 AGE_NN1 of_PRF DNA_NN1 ILLUSTRATIONS_NN2 
As_CJS the_AT0 importance_NN1 of_PRF the_AT0 discovery_NN1 by_PRP Watson_NP0 and_CJC Crick_NP0 became_VVD known_VVN to_PRP scientists_NN2 and_CJC nonscientists_NN2 ,_PUN there_EX0 arose_VVD a_AT0 great_AJ0 variety_NN1 of_PRF depictions_NN2 of_PRF DNA_NN1 ._SENT Some_DT0 variations_NN2 are_VBB these_DT0 :_PUN 
•_PUN The_AT0 sugar-phosphate_AJ0 chains_NN2 can_VM0 be_VBI depicted_VVN as_PRP flat_AJ0 ribbons_NN2 ,_PUN round_PRP rails_NN2 or_CJC a_AT0 series_NN0 of_PRF sugar_NN1 and_CJC phosphate_NN1 molecules_NN2 ._SENT 
•_PUN The_AT0 base_NN1 pairs_NN2 can_VM0 be_VBI indicated_VVN as_PRP one_CRD horizontal_AJ0 piece_NN1 or_CJC as_PRP two_CRD different_AJ0 parts_NN2 of_PRF a_AT0 horizontal_AJ0 piece_NN1 ._SENT In_PRP the_AT0 latter_DT0 case_NN1 ,_PUN the_AT0 parts_NN2 may_VM0 be_VBI labeled_VVN as_PRP A_ZZ0 ,_PUN T_ZZ0 ,_PUN G_ZZ0 and_CJC C_ZZ0 ._SENT 
•_PUN The_AT0 bases_NN2 can_VM0 be_VBI depicted_VVN as_PRP symmetrical_AJ0 pairs_NN2 or_CJC as_PRP asymmetrical_AJ0 pairs_NN2 ._SENT 
•_PUN DNA_NN1 can_VM0 be_VBI depicted_VVN in_PRP monochrome_NN1 ,_PUN or_CJC its_DPS different_AJ0 parts_NN2 can_VM0 be_VBI shown_VVN in_PRP different_AJ0 colors_NN2 ._SENT 
•_PUN In_PRP most_DT0 cases_NN2 ,_PUN DNA_NN1 is_VBZ shown_VVN vertically_AV0 ,_PUN but_CJC it_PNP could_VM0 also_AV0 be_VBI shown_VVN horizontally_AV0 or_CJC diagonally_AV0 ._SENT 
There_EX0 is_VBZ a_AT0 limit_NN1 to_PRP these_DT0 variations_NN2 ,_PUN namely_AV0 the_AT0 underlying_AJ0 structure_NN1 of_PRF DNA_NN1 ._SENT Even_AV0 so_AV0 ,_PUN these_DT0 variations_NN2 prompt_VVB questions_NN2 :_PUN Why_AVQ would_VM0 an_AT0 illustrator_NN1 choose_VVB one_CRD combination_NN1 of_PRF aesthetic_AJ0 features_NN2 while_CJS a_AT0 different_AJ0 illustrator_NN1 chooses_VVZ a_AT0 different_AJ0 combination_NN1 ?_SENT What_DTQ does_VDZ the_AT0 illustrator_NN1 want_VVB the_AT0 audience_NN1 to_TO0 know_VVI about_PRP DNA_NN1 ?_SENT 
Here_AV0 I_PNP speculate_VVB about_PRP those_DT0 questions_NN2 ._SENT There_EX0 are_VBB two_CRD principal_AJ0 populations_NN2 that_CJT consume_VVB visual_AJ0 depictions_NN2 of_PRF DNA_NN1 ._SENT One_PNI comprises_VVZ scientists_NN2 and_CJC science_NN1 students_NN2 ,_PUN plus_PRP physicians_NN2 and_CJC medical_AJ0 students_NN2 ._SENT When_CJS they_PNP see_VVB DNA_NN1 in_PRP their_DPS textbooks_NN2 ,_PUN it_PNP is_VBZ helpful_AJ0 that_CJT visual_AJ0 depictions_NN2 provide_VVB precise_AJ0 details_NN2 :_PUN that_CJT the_AT0 sugar-phosphate_AJ0 chains_NN2 look_VVB different_AJ0 from_PRP the_AT0 base_NN1 pairs_NN2 ,_PUN and_CJC that_CJT each_DT0 base_NN1 has_VHZ its_DPS own_DT0 unique_AJ0 signal_NN1 ,_PUN whether_CJS color_NN1 or_CJC labels_NN2 of_PRF A_ZZ0 ,_PUN T_ZZ0 ,_PUN G_ZZ0 or_CJC C_ZZ0 ._SENT This_DT0 is_VBZ important_AJ0 information_NN1 to_PRP the_AT0 population_NN1 in_PRP question_NN1 ._SENT 
Another_DT0 population_NN1 consists_VVZ of_PRF consumers_NN2 who_PNQ need_VVB little_AJ0 detail_NN1 in_PRP the_AT0 depictions_NN2 they_PNP see_VVB :_PUN It_PNP is_VBZ enough_AV0 to_TO0 perceive_VVI only_AV0 that_DT0 DNA_NN1 embodies_VVZ a_AT0 double_AJ0 helix_NN1 and_CJC four_CRD base_NN1 pairs_NN2 ._SENT Why_AVQ is_VBZ this_DT0 ?_SENT 
I_PNP suggest_VVB that_CJT simpler_AJC depictions_NN2 of_PRF the_AT0 molecule_NN1 have_VHB minimal_AJ0 didactic_AJ0 value_NN1 because_CJS they_PNP serve_VVB audiences_NN2 that_CJT have_VHB little_AV0 need_VVB to_TO0 know_VVI what_DTQ the_AT0 parts_NN2 are_VBB ._SENT It_PNP is_VBZ sufficient_AJ0 for_PRP this_DT0 audience_NN1 that_CJT a_AT0 stripped-down_AJ0 picture_NN1 of_PRF DNA_NN1 tells_VVZ the_AT0 viewer_NN1 that_CJT if_CJS a_AT0 product_NN1 ,_PUN a_AT0 vision_NN1 or_CJC a_AT0 brand_NN1 includes_VVZ a_AT0 picture_NN1 of_PRF DNA_NN1 ,_PUN then_AV0 it_PNP is_VBZ "_PUQ scientific_AJ0 ._SENT "_PUQ Before_PRP April_NP0 1953_CRD ,_PUN one_PNI might_VM0 have_VHI claimed_VVN that_CJT something_PNI is_VBZ scientific_AJ0 by_PRP showing_VVG the_AT0 outline_NN1 of_PRF an_AT0 optical_AJ0 microscope_NN1 ,_PUN or_CJC by_PRP showing_VVG a_AT0 two-dimensional_AJ0 image_NN1 of_PRF an_AT0 atom_NN1 with_PRP electrons_NN2 orbiting_VVG a_AT0 nucleus_NN1 ._SENT 
Now_AV0 we_PNP are_VBB in_PRP a_AT0 different_AJ0 epistemic_AJ0 moment_NN1 ._SENT A_AT0 common_AJ0 way_NN1 to_TO0 say_VVI that_CJT something_PNI is_VBZ scientific_AJ0 is_VBZ to_TO0 associate_VVI it_PNP with_PRP a_AT0 simple_AJ0 depiction_NN1 of_PRF DNA_NN1 ,_PUN and_CJC for_PRP this_DT0 purpose_NN1 there_EX0 is_VBZ no_AT0 reason_NN1 to_TO0 differentiate_VVI the_AT0 physical_AJ0 details_NN2 of_PRF DNA_NN1 with_PRP aesthetic_AJ0 details_NN2 ._SENT 
Between_PRP those_DT0 two_CRD audiences_NN2 and_CJC their_DPS needs_NN2 are_VBB other_AJ0 kinds_NN2 of_PRF audiences_NN2 ._SENT A_AT0 notable_AJ0 one_PNI constitutes_VVZ nonscientists_NN2 who_PNQ are_VBB curious_AJ0 about_PRP science_NN1 ,_PUN e.g._AV0 those_DT0 who_PNQ read_VVB the_AT0 science_NN1 section_NN1 in_PRP the_AT0 New_AJ0 York_NP0 Times_NN2 or_CJC the_AT0 Guardian_NN1 ._SENT What_DTQ does_VDZ this_DT0 audience_NN1 expect_VVB of_PRF illustrations_NN2 of_PRF DNA_NN1 ?_SENT Perhaps_AV0 they_PNP need_VVB more_DT0 empirical_AJ0 detail_NN1 than_CJS the_AT0 simpler_AJC depictions_NN2 but_CJC not_XX0 the_AT0 same_DT0 detail_NN1 that_CJT one_PNI finds_VVZ in_PRP medical_AJ0 textbooks_NN2 ._SENT 
My_DPS comments_NN2 may_VM0 sound_VVI elitist_AJ0 :_PUN Scientists_NN2 need_VVB many_DT0 empirical_AJ0 details_NN2 while_CJS nonscientists_NN2 are_VBB satisfied_AJ0 with_PRP few_DT0 ._SENT But_CJC I_PNP emphasize_VVB that_CJT there_EX0 is_VBZ a_AT0 spectrum_NN1 of_PRF consumers_NN2 ._SENT It_PNP includes_VVZ scientists_NN2 ,_PUN physicians_NN2 ,_PUN science_NN1 teachers_NN2 ,_PUN medical_AJ0 students_NN2 and_CJC more_AV0 ._SENT There_EX0 is_VBZ no_AT0 single_AJ0 formula_NN1 for_PRP how_AVQ to_TO0 depict_VVI DNA_NN1 because_CJS there_EX0 is_VBZ no_AT0 single_AJ0 audience_NN1 to_TO0 depict_VVI it_PNP for_PRP ._SENT 
The_AT0 golden_AJ0 age_NN1 of_PRF depicting_VVG DNA_NN1 continues_VVZ ._SENT Illustrations_NN2 in_PRP genetics_NN1 textbooks_NN2 may_VM0 become_VVI more_AV0 detailed_AJ0 for_PRP the_AT0 purpose_NN1 of_PRF communicating_VVG more_DT0 empirical_AJ0 knowledge_NN1 ,_PUN but_CJC the_AT0 simpler_AJC pictures_NN2 remain_VVB useful_AJ0 for_PRP conveying_VVG a_AT0 simpler_AJC message_NN1 that_CJT here_AV0 is_VBZ something_PNI scientific_AJ0 ._SENT I_PNP add_VVB two_CRD more_DT0 phases_NN2 below_AV0 ._SENT 
PHASE_NN1 THREE_CRD :_PUN GENETIC_AJ0 ENGINEERING_NN1 
Genetic_AJ0 engineering_NN1 is_VBZ a_AT0 technology_NN1 that_CJT uses_VVZ recombinant_AJ0 DNA_NN1 (_PUL rDNA_NN1 )_PUR to_TO0 transfer_VVI the_AT0 genotype_NN1 of_PRF a_AT0 trait_NN1 from_PRP one_CRD organism_NN1 to_PRP another_DT0 ._SENT A_AT0 desirable_AJ0 trait_NN1 is_VBZ identified_VVN ;_PUN the_AT0 genes_NN2 that_CJT code_VVB for_PRP that_DT0 trait_NN1 are_VBB located_VVN ;_PUN rDNA_NN1 captures_VVZ the_AT0 relevant_AJ0 DNA_NN1 from_PRP the_AT0 source_NN1 organism_NN1 and_CJC then_AV0 inserts_VVZ it_PNP into_PRP the_AT0 genome_NN1 of_PRF a_AT0 target_NN1 organism_NN1 ,_PUN which_DTQ can_VM0 be_VBI from_PRP a_AT0 different_AJ0 species_NN0 ._SENT When_CJS this_DT0 works_VVZ properly_AV0 ,_PUN the_AT0 trait_NN1 manifests_VVZ itself_PNX in_PRP the_AT0 target_NN1 organism_NN1 ._SENT Genetically_AV0 modified_AJ0 foods_NN2 are_VBB vivid_AJ0 proof_NN1 that_CJT genetic_AJ0 engineering_NN1 is_VBZ real_AJ0 ._SENT The_AT0 ultimate_AJ0 genetically_AV0 modified_AJ0 organism_NN1 is_VBZ a_AT0 creature_NN1 that_CJT has_VHZ acquired_VVN bioluminescence_NN1 ,_PUN e.g._AV0 kittens_NN2 that_CJT glow_VVB in_PRP the_AT0 dark_NN1 because_CJS genes_NN2 for_PRP luminescence_NN1 have_VHB been_VBN inserted_VVN in_PRP vitro_NN1 into_PRP their_DPS genomes_NN2 ._SENT 
How_AVQ then_AV0 is_VBZ DNA_NN1 depicted_VVN in_PRP genetic_AJ0 engineering_NN1 ?_SENT The_AT0 core_NN1 purpose_NN1 of_PRF visual_AJ0 depictions_NN2 of_PRF DNA_NN1 in_PRP genetic_AJ0 engineering_NN1 is_VBZ to_TO0 show_VVI that_CJT a_AT0 segment_NN1 of_PRF DNA_NN1 is_VBZ extracted_VVN from_PRP one_CRD organism_NN1 and_CJC inserted_VVN into_PRP another_DT0 ._SENT 
But_CJC if_CJS scientists_NN2 are_VBB doing_VDG genetic_AJ0 engineering_NN1 ,_PUN then_AV0 it_PNP is_VBZ desirable_AJ0 to_TO0 show_VVI them_PNP doing_VDG so_AV0 ._SENT Depictions_NN2 of_PRF genetic_AJ0 engineering_NN1 often_AV0 show_VVB a_AT0 person_NN1 wearing_VVG a_AT0 white_AJ0 lab_NN1 coat_NN1 (_PUL because_CJS this_DT0 says_VVZ that_CJT the_AT0 person_NN1 is_VBZ a_AT0 scientist_NN1 )_PUR ,_PUN and_CJC they_PNP show_VVB that_CJT the_AT0 person_NN1 is_VBZ in_PRP the_AT0 process_NN1 of_PRF moving_VVG a_AT0 segment_NN1 of_PRF DNA_NN1 from_PRP a_AT0 source_NN1 organism_NN1 to_PRP a_AT0 target_NN1 organism_NN1 ._SENT 
The_AT0 DNA_NN1 molecule_NN1 is_VBZ much_AV0 too_AV0 small_AJ0 to_TO0 be_VBI seen_VVN by_PRP an_AT0 optical_AJ0 microscope_NN1 ,_PUN let_VVB alone_AV0 the_AT0 human_AJ0 eye_NN1 ._SENT Were_VBD the_AT0 scientist_NN1 depicted_VVN at_PRP a_AT0 scale_NN1 making_VVG their_DPS humanity_NN1 visible_AJ0 ,_PUN a_AT0 piece_NN1 of_PRF DNA_NN1 could_VM0 not_XX0 be_VBI depicted_VVN at_PRP the_AT0 same_DT0 scale_NN1 ._SENT 
The_AT0 solution_NN1 is_VBZ to_TO0 exaggerate_VVI the_AT0 size_NN1 of_PRF the_AT0 DNA_NN1 segment_NN1 ._SENT The_AT0 genetic_AJ0 material_NN1 may_VM0 seem_VVI to_TO0 be_VBI about_PRP 20_CRD centimeters_NN2 in_PRP length_NN1 ,_PUN which_DTQ is_VBZ to_TO0 say_VVI that_CJT the_AT0 illustrator_NN1 depicts_VVZ humans_NN2 at_PRP a_AT0 human_AJ0 scale_NN1 but_CJC depicts_VVZ DNA_NN1 as_CJS something_PNI millions_CRD of_PRF times_NN2 larger_AJC than_CJS it_PNP really_AV0 is_VBZ ._SENT If_CJS one_PNI is_VBZ going_VVG to_TO0 illustrate_VVI a_AT0 nanoscale_AJ0 process_NN1 like_PRP genetic_AJ0 engineering_NN1 ,_PUN while_CJS also_AV0 putting_VVG scientists_NN2 into_PRP the_AT0 illustration_NN1 ,_PUN then_AV0 it_PNP is_VBZ necessary_AJ0 to_TO0 distort_VVI the_AT0 scale_NN1 of_PRF the_AT0 DNA_NN1 ._SENT Didactic_AJ0 intent_NN1 determines_VVZ this_DT0 aesthetic_AJ0 decision_NN1 ._SENT Here_AV0 Google_NP0 helps_VVZ us_PNP ._SENT Search_NN1 for_PRP "_PUQ genetic_AJ0 engineering_NN1 "_PUQ and_CJC select_VVB "_PUQ images_NN2 ._SENT "_PUQ One_PNI can_VM0 see_VVI how_AVQ the_AT0 human_AJ0 scale_NN1 and_CJC the_AT0 molecular_AJ0 scale_NN1 are_VBB made_VVN to_TO0 fit_VVI into_PRP one_CRD image_NN1 ._SENT 
Phase_NN1 three_CRD does_VDZ not_XX0 represent_VVI an_AT0 end_NN1 to_PRP phase_NN1 two_CRD ._SENT On_PRP the_AT0 contrary_NN1 ,_PUN the_AT0 two_CRD can_VM0 occupy_VVI the_AT0 same_DT0 time_NN1 period_NN1 ,_PUN because_CJS different_AJ0 illustrators_NN2 have_VHB different_AJ0 didactic_AJ0 intentions_NN2 ._SENT 
PHASE_NN1 FOUR_CRD :_PUN SYNTHETIC_AJ0 BIOLOGY_NN1 
Synthetic_AJ0 biology_NN1 is_VBZ a_AT0 sophisticated_AJ0 variation_NN1 of_PRF genetic_AJ0 engineering_NN1 ._SENT Again_AV0 ,_PUN a_AT0 desirable_AJ0 trait_NN1 is_VBZ identified_VVN ,_PUN and_CJC the_AT0 genes_NN2 that_CJT code_VVB for_PRP that_DT0 trait_NN1 are_VBB located_VVN ._SENT But_CJC instead_AV0 of_PRF deriving_VVG the_AT0 DNA_NN1 from_PRP a_AT0 living_AJ0 organism_NN1 ,_PUN one_PNI can_VM0 assemble_VVI it_PNP in_PRP a_AT0 chemistry_NN1 lab_NN1 where_CJS there_EX0 are_VBB supplies_NN2 of_PRF A_ZZ0 ,_PUN T_ZZ0 ,_PUN G_ZZ0 and_CJC C_ZZ0 ,_PUN plus_PRP sugar_NN1 molecules_NN2 and_CJC phosphate_NN1 molecules_NN2 ._SENT Synthetic_AJ0 biology_NN1 then_AV0 acquires_VVZ a_AT0 sense_NN1 that_CJT it_PNP is_VBZ a_AT0 process_NN1 of_PRF design_NN1 and_CJC construction_NN1 ,_PUN like_PRP civil_AJ0 engineering_NN1 ._SENT Depictions_NN2 of_PRF DNA_NN1 sequences_NN2 emphasize_VVB that_CJT they_PNP have_VHB been_VBN designed_VVN ,_PUN constructed_VVN and_CJC delivered_VVN to_PRP the_AT0 right_AJ0 places_NN2 ,_PUN like_PRP the_AT0 pieces_NN2 of_PRF a_AT0 building_NN1 or_CJC a_AT0 bridge_NN1 ._SENT Engineering_NN1 practices_NN2 govern_VVB the_AT0 visual_AJ0 representation_NN1 of_PRF DNA_NN1 ._SENT 
When_CJS the_AT0 Woodrow_NP0 Wilson_NP0 Center_NN1 first_ORD launched_VVD its_DPS Synthetic_AJ0 Biology_NN1 Project_NN1 more_AV0 than_CJS 10_CRD years_NN2 ago_AV0 ,_PUN the_AT0 opening_AJ0 page_NN1 on_PRP its_DPS web_NN1 site_NN1 showed_VVD cranes_NN2 ,_PUN construction_NN1 workers_NN2 in_PRP hard_AJ0 hats_NN2 and_CJC other_AJ0 signs_NN2 that_CJT synthetic_AJ0 biology_NN1 builds_VVZ its_DPS own_DT0 DNA_NN1 according_VVG to_PRP its_DPS own_DT0 preferences_NN2 ._SENT How_AVQ quaint_AJ0 it_PNP seems_VVZ for_PRP classical_AJ0 genetic_AJ0 engineering_NN1 to_TO0 rely_VVI on_PRP organic_AJ0 sources_NN2 of_PRF DNA_NN1 ._SENT More_AV0 recently_AV0 ,_PUN however_AV0 ,_PUN that_DT0 image_NN1 has_VHZ been_VBN deleted_VVN in_PRP favor_NN1 of_PRF an_AT0 emphasis_NN1 on_PRP building_NN1 muscles_NN2 with_PRP the_AT0 benefit_NN1 of_PRF synthetic_AJ0 vitamins_NN2 and_CJC supplements_NN2 ._SENT 
