It's extremely hard to create an adaptive robot, especially by hand
He shows an example of a nanoped, where the first video is what the engineers guessed would be best, where it could barely moved. Then he showed some results from the evolutionary algo, which led to it almost being able to run
there was also case where the robot moved sideways - example of unintuitive results
It allows for you to optimized the "brain" and the body at the same time
example: architecture search of neural net while also randomizing body parts