Name the nickname with age of 4.9
CREATE TABLE "geography_and_environment" (
  "island" text,
  "nickname" text,
  "area" text,
  "population_as_of_2010" real,
  "highest_point" text,
  "elevation" text,
  "age_ma" text
);
SELECT "nickname" FROM "geography_and_environment" WHERE "age_ma"='4.9';