In a groundbreaking study, researchers explored a key evolutionary transition – from animals living in water to living on land – using a robot called MuddyBot.
Was a tail needed for ancient vertebrates to make the first steps from water onto dry land? That’s one of the conclusions of a new groundbreaking study, published in the journal Science on July 8, 2016.
The researchers studied this question by observing amphibious fish, then by building a robot they called MuddyBot and watching its movements. Finally, they applied mathematical models of movement to what they learned.
… long been obsessed with the question of how the first creatures moved onto land.
He and his colleagues – from Georgia Institute of Technology, Carnegie Mellon University, Clemson University and National Institute for Mathematical and Biological Synthesis – explored the behavior and body mechanics of the African mudskipper, an amphibious fish that lives in tidal areas near shore.
Mudskippers are known to use their front fins and tail to move on land with a “crutching” motion. The researchers studied their motion in detail, recording the movements of mudskippers in a lab in a recreated environment they tried to make as similar as possible to ancient riverbanks, where early land-dwellers might have emerged. Goldman said:
We found when mudskippers are using their tail on a sufficiently inclined sandy slope they do pretty well and when they don’t, they don’t do well.
Next, the researchers developed a simplified, mudskipper-like version of a robot, which they call MuddyBot. They used MuddyBot to find out which coordinated motions of limb and tail were most effective on granular surfaces of different inclines.
Finally, the researchers used a mathematical and engineering method called geometric mechanics to analyze all the possible ways the MuddyBot can move in space and on different surfaces. They said this method helped them:
…determine what types of movement may or may not have allowed the creature to pull itself up onto a sandy or muddy slope.
Their conclusion: the first creatures to move from water to land may have had tails and may have used a crutching motion to move out of the water.
Bottom line: Researchers explored how ancient creatures moved from water to land, in part via a robot called MuddyBot.