 
 (defun evolution ()
   (draw-world)
-  (fresh-line)
-  (let ((str (read-line)))
+  (newline)
+  (let ((str (read-string "Steps (or 'quit'): ")))
     (cond ((equal str "quit") ())
           (t (let ((x (parse-integer str :junk-allowed t)))
                (if x

  (add-plants))

(defun draw-world ()
  (loop for y
     below *height*
     do (progn (fresh-line)

  (let ((e (animal-energy animal)))
    (when (>= e *reproduction-energy*)
      (setf (animal-energy animal) (ash e -1))
      (let ((animal-nu (copy-animal animal))
            (genes     (copy-list (animal-genes animal)))
            (mutation (random 8)))
        (setf (nth mutation genes) (max 1 (+ (nth mutation genes) (random 3) -1)))
