Bone robot shows the first steps on dry land
Our earliest ancestors adapted more quickly to life on dry land than scientists used to think, according to a robot that scientists have built from old bones and new tiny motors.
Modern robot technology can now show us how one of our very early ancestors moved about on Earth. Palaeontologists have long wondered which gait the first amniotes used. Amniotes originated some 350 million years ago, and they are the ancestors of reptiles, birds and mammals. Amniotes differ from amphibians by not needing to live the first part of their lives in water (as do frogs, say, as tadpoles).
Scientists from the Humboldt University in Germany have made CT scans of a remarkably well-preserved fossil of the Orobates pabsti amniote, which lived some 285 million years ago. Subsequently, they recreated its skeleton, so they could see into which angles the bone joints could be turned, before they built motors to fit into the joints. The scientists also had a series of well-preserved footprints that had been discovered near the fossil, so they could experiment with the robot’s step length, spinal column flexibility and speed in order to find the correct gait.
The result shows that the early amniote moved in a way that palaeontologists believed to have appeared only much later in evolution. It walked with relatively stretched legs and a less pronounced twist of the spinal column than do reptiles such as salamanders today. So the amniote saved energy as it moved about.
The scientists now aim to use their method to solve other evolutionary mysteries, such as how the first flying animals took flight, how our own ancestors got up and stood on two legs, and how some mammals took the leap from dry land to water to become marine mammals.