Land-walking fish and a robot show value of an additional appendage in crawling up sandy slopes
Rob Felt/Georgia Tech
Nothing conquers a slippery slope like a good twitch of the tail, say researchers exploring how vertebrates could have taken the first treacherous steps on land.
When early vertebrates invaded land 360 million years or more ago, their tails might have been critical in helping them climb sloping sand or mud, suggests physicist Daniel Goldman of Georgia Tech in Atlanta. These surfaces can suddenly shift from a solid heap to a flowing slide that sends climbers slipping and flailing. Using a tail the right way in a hop-swing kind of gait, however, lets little fish called mudskippers and a dune-invader robot get going on slippery slopes, Goldman and an interdisciplinary team report in the July 8 Science. It’s the latest in research on how animals and robots can cope with treacherous surfaces.
With a well-timed tail push, “you can then get