The sixth grade science students created a timeline placing the formation of Earth and the moon and the evolution of living things on earth on a 100 yard scale (representing 4.6 billion years).  It begins with the formation of the earth and moon (you can barely see that sign next to the school building), the next sign in the timeline (also barely visible) is the appearance of bacteria.  The signs that appear much more clearly in the foreground depict the evolution of various groups of plants and animals.  Here is the entire sequence they used:

  beginning -- formation of Earth/moon
  18 yards -- bacteria appear
  87 yards -- simple ocean-dwelling animals
  89 yards -- complex ocean-dwelling animals
  90 yards -- fish
  91 yards -- land plants
  92 yards -- insects
  94 yards -- amphibians
  94.5 yards -- small reptiles
  95 yards -- dinosaurs
  95.5 yards -- small mammals
  97 yards -- birds
  99 yards -- flowering plants
  99.5 yards -- large mammals
  99 yards, 35.5 inches -- humans
100 yards -- today

Nice job sixth graders!!!