Robots and Ancient Fish: A New Approach to Understanding the Evolutionary Leap from Water to Land

The transition from aquatic to terrestrial life is one of the most fascinating chapters in the story of life on Earth. It marked a pivotal evolutionary shift, as the ancestors of today’s land animals crawled out of the water and began exploring new terrains about 390 million years ago. But how exactly did those early creatures manage to move from swimming to walking? With fossil evidence providing only a fragmented view, a team of researchers is turning to an unlikely ally: robots.

In a study published in Science Robotics, a collaborative team of roboticists, palaeontologists, and biologists from the University of Cambridge is pioneering the use of "palaeo-inspired robotics" to simulate the movements of ancient fish. Their goal? To better understand how fins evolved into limbs capable of supporting weight on land.

Lead researcher Dr. Michael Ishida from Cambridge's Department of Engineering explains the challenge: "Fossils only give us a partial picture of how ancient species made their move to land. We can learn a lot from studying their bones, but bones alone don’t reveal how these creatures moved. That’s where our robots come in – helping us simulate the movements and behaviors of species that have long since disappeared."

Robots Bridging the Gap

At Cambridge's Bio-Inspired Robotics Laboratory, Professor Fumiya Iida and his team are developing energy-efficient robots inspired by the movement of animals. With the support of the Human Frontier Science Program, they're taking cues from modern "walking fish" like mudskippers and combining them with data from fossilized remains of ancient species.

The process involves creating robotic skeletons that replicate the anatomy of these early fish. "In the lab, we can’t exactly teach a living fish to walk differently, and we certainly can’t ask a fossil to get up and move," says Ishida. "Instead, we build robotic models that mimic their skeletal structures, complete with mechanical joints that act like muscles and ligaments."

Simulating Ancient Movement

The team aims to use these robots to run experiments that shed light on the locomotion of early land explorers. One of their key objectives is to analyze the energy requirements of different walking patterns, testing which movements might have been the most efficient. This approach can help validate or challenge existing theories about how these ancient animals evolved.

The robotic models also provide a new way to address the limitations of fossil records. Since many ancient species from this time period are only known from partial skeletons, scientists often have to make educated guesses about their mobility. Robots allow researchers to test these assumptions and refine their understanding of how early vertebrates moved.

An Emerging Field

Using robots to study extinct species is a relatively new field of research. While robotics has long been used to understand the movement of living animals, very few research groups have applied this technology to the biomechanics of ancient life forms. "It's a natural fit, though," says Ishida. "Robots can offer insights that we just can't get from studying fossils or living species alone."

By bridging the gap between fossil evidence and real-world mechanics, the researchers hope their work will inspire other scientists to explore robotics as a tool for studying ancient life. The potential goes beyond evolutionary biology – the approach could also foster new collaborations between engineers and researchers in fields like palaeontology, biomechanics, and robotics.

Looking Ahead

The project is still in its early stages, with the team currently building their palaeo-robots. However, they aim to have preliminary results within a year. The researchers are optimistic that their robotic models will deepen our understanding of the evolutionary shift from water to land and potentially uncover why these early land pioneers moved the way they did.

The research is supported by the Human Frontier Science Program, with Professor Fumiya Iida serving as the senior author and Dr. Michael Ishida as a postdoctoral researcher. Their innovative use of robotics might just help answer one of the oldest questions in evolutionary history – how the first creatures made the leap to land, paving the way for all terrestrial life that followed.