Two years ago, we had a scheduled visit from high-profile scientists. Because our university wanted everything to look great for these important visitors, the university applied wax to the floor the day before. The floor was clean and shiny, which looked nice, but it was also much more slippery! We tried the gait our algorithm had previously learned, which we had tested many times to make sure it would work for these visitors, but it did not work at all. Fortunately, however, our robot can adapt! We launched our adaption algorithm, and a few minutes later, our robot was walking again on the newly waxed floor. As you can imagine, our visitors loved our work.
Another surprise was the following: To create a diversity of behaviors, we used evolution to produce a variety of different ways to walk. We did that by selecting for many different types of walking, measured as robots that have their feet touching the ground different percentages of the time (100%, 75%, ..., 25%, 0%). We thought evolution of course would not be able to solve the 0% case, but it surprised us! It flipped over on it's back and crawled on its elbows with its feet in the air.