gistfile1.clj

(defn fitness-fn [target]
  (fn [data]
    (Math/abs (- target data))))

(defn evolve [sources fitness]
  (let [next-gen (for [source sources
                       x (range 5)] ;; try 5 mutations for each source
                   (+ source (- 20 (rand-int 40))) ; go up or down by up to 20
                   )]
    (take (count sources) (sort-by fitness next-gen))))

(defn start [seeds goal]
  (let [fitness (fitness-fn goal)
        num-tries 50]
    (nth (iterate #(evolve % fitness) seeds)
         num-tries)))

(start (range 10) 1000)