What identities do the genus/species arabidopsis thaliana have? 
CREATE TABLE "table1_15417439_1" (
  "genus_species" text,
  "common_name" text,
  "accession_number" text,
  "length" text,
  "similarity" text,
  "identity" text
);
SELECT "identity" FROM "table1_15417439_1" WHERE "genus_species"='Arabidopsis thaliana';