In the first episode of LIFE, a new series from the makers of Planet Earth, the special adaptations of the basilisk lizard are featured to show how animals have evolved some remarkable strategies to stay alive. By running on water, the basilisk “Jesus Christ” lizard has even challenged the established mechanics for legged locomotion; while an inventor in 1988 claims to have solved the mechanics for water-running over two decades ago.
If you’re looking to be impressed by aquatic adaptations, look no further than the animal kingdom: specifically the 11-part nature special called LIFE, co-produced by the BBC and The Discovery Channel. With the same cinematic power as the Planet Earth series, LIFE introduces the elements of adaptation, evolution, and resilience told through time-bending slow motion and epic aerial shots.
If you missed the first episodes, and the encore presentations, you can still see a short clip of the basilisk running on water in this preview on YouTube. Nicknamed the “Jesus Lizard” or “Jesus Christ Lizard” for its seemingly miraculous ability to walk on water, the basilisk’s movement had not been thoroughly analyzed until as recently as 2004. Researchers Shi-Tong Tonia Hsieh and George Lauder challenged the idea that there is a simple continuum in the strategy animals use to move across surfaces – in other words, they wondered if the lizard ran differently in order to stay upright on the surface rather than just running very quickly with large feet.
According to detailed video analysis, the lizard’s stride on the water can be broken into three phases: the slap, the stroke, and the recovery. The lizard generates enough vertical force to stay up during the slap phase, and lateral force to move forward during the stroke (source). However, according to Hsieh and Lauder, “the mechanics of lizard water-running challenge a major established rule of legged locomotion known as the spring-mass model. In the model, energy is stored in an animal’s limb during the start of the contact, or slap, phase and then released to help propel the animal forward” (source). Hsieh and Lauder conclude that this does not occur in the lizard, and liken the movement to that of a piston rather than a spring.
These results show that it’s not just a matter of running fast with big feet, but support that there is a different model of locomotion for running on a liquid surface. This is unfortunate for anyone who has dreamed of running down the pool with swim fins on, and also for inventor Peter B. Tomlinson, the man who holds US Patent No. US4787871 for Water Surface Running Fins for the Feet.
At a glance, Tomlinson’s invention looks similar to the foot design of the basilisk lizard. The fin provides a large, flat, rigid surface for the slap phase, and even a semi-collapsed state for the recovery phase. However, because water-running requires a different model of locomotion than running on land, it is hard to imagine something like a running fin working on humans without extensive training to alter the running mechanics.
Tomlinson’s vision of Water Surface Running Fins being used for exercise, competitive races, and even lifeguard equipment, will remain a fantasy for the time being. But just as we were once inspired by a bird’s winged flight, perhaps water-running fins are the next great invention to be modeled after life’s adaptations.