Researchers at the Harvard School of Engineering and Applied Sciences. John A. Paulson (SEAS) explained how fish could develop the ability to walk underwater.

The neural networks necessary for walking may already have been present in the common ancestor of stingrays and mammals about 420 million years ago. Millions of years before the first fearless fish crawled out of the ocean. But how exactly did our ancient aquatic ancestors walk? SEAS researchers have developed a mathematical framework to explain how underwater walking could have evolved.

Scientists found that the ancient ancestors of stingrays and humans could achieve efficient underwater walking using available body morphology, with very little energy and simple controls. Ancient vertebrates had everything they needed to walk underwater millions of years before landfall. The research is published in The Royal Society Interface journal.

In their work, the scientists showed that the alternating left-right gait arose using a simple algorithm based on reinforcement learning. The researchers built a bipedal robot to test their theory. The results confirmed the scientists’ assumption.

This research not only sheds light on the past, but also paves the way for the development of more efficient bioinspired robots in the future, the scientists note. In addition to energy-efficient locomotion, scientists have found the robot has the ability to recover from serious disruptions.