Today we got outside to do an evolution by natural selection activity. Sexual reproduction yields variation (and mutations) among members of a population. Our birds (students) had variation in their beak shapes (spoons, forks, forceps, and knives) as they foraged on the lawn for different sized and colored beans. We found that nature would favor the "spoon beak" shape and those members would pass that gene on to their offspring. After awhile, the "knife and forcep beak" genes would be eliminated.