The story keeps getting retold because people assume the trajectory is obvious. Build something that looks human, keep improving it, and one day the copy becomes indistinguishable from the original. What’s happening on the ground is stranger than that.

At CES 2026, Boston Dynamics’ Atlas demonstrated wrists that bent backward and a torso that spun a full 180 degrees. Elsewhere, humanoid robots are beginning to diverge in even more striking ways. Some can swap their own batteries by reaching both arms behind their backs.

Others walk on reverse-jointed legs. The human silhouette is still there, but the movements inside it have gone somewhere else entirely. There’s an obvious objection here.

Hasn’t copying nature worked before? Sometimes. Gecko toe pads gave engineers the idea for dry adhesives. Sharkskin texture showed up in competitive swimsuits.

But in both cases, engineers borrowed the physics underneath, not the shape. The ones who tried to copy natural forms wholesale usually hit a wall. For centuries, people tried to build ornithopters that flapped like birds, but none became a practical path to human flight.

The Wright brothers got off the ground not because they simply imitated, but because they moved beyond flapping and focused on the principles of lift and control. If evolution has spent millions of years refining a design, why don’t engineers just copy it? That question went to the Hubo Lab at KAIST.

The lab built HUBO, the robot that won the 2015 DARPA Robotics Challenge, and today it’s led by Prof. Park Hae-won. His team’s recent work gives a sense of the range.

Humanoid legs that sprint at 12.6 kilometers per hour. A quadruped robot that walks straight up vertical walls. A one-legged hopper that launches into mid-air somersaults and lands on the same leg.

The KAIST humanoid robot and the research team. From the center of the back row, clockwise Hae-Won Park, Dongyun Kang, Hajun Kim, JongHun Choe, Min-Su Kim Image: KAIST Mimicking nature is not always the right answer. At 12.6 kilometers per hour, a person has to break into a run.

A robot built by Prof. Park Hae-won’s team at KAIST can sprint at that speed on two legs. It glides through motions that look like Michael Jackson’s moonwalk and picks its way over rough terrain with a duck-like waddle.

One place to start is biology. Roboticists have been borrowing nature’s tricks for decades. Prof. Park’s robots do look like they come from that tradition.

But he works the other way around. Instead of studying an animal to build one, he picks a problem and builds a machine to solve it. “If you’re developing technology for high-speed movement, wheels can be an efficient choice,” Prof.

Park said. “There’s no need to mimic the motion of a cheetah.” A car on wheels outruns a cheetah. Evolution never set out to build the fastest runner.

It built the one most likely to survive. “Studying natural organisms gives us a sense of the level of performance that can be reached when something is well designed,” Prof. Park said.

“It serves as a useful reference for setting direction during research and development.” He added “It’s important to view nature as one reference point. Rather than replicating it directly, it’s more appropriate to use it as a source of ideas.” Humanoids face the same question. A human body runs on muscles, tendons, and chemical energy.

A robot runs on metal frames, motors, and electricity. To copy human movement faithfully you’d need artificial muscles, but motors still tend to outperform commercially available artificial muscles in many practical metrics. So why handicap a robot by forcing it to move like a body it doesn’t have?

MARVEL, a quadruped robot from Prof. Park’s lab, was designed for grimmer work. Researchers wanted a robot that could move freely across the steel structures of shipyards, bridges, and large storage tanks.

Places where maintenance crews risk fatal falls. The quadruped robot MARVEL climbing a metal tank. Image: KAIST Gecko feet or insect claws might sound like the right model for a wall-climbing robot.

But real industrial steel is rusted, layered in old paint, and caked with grime. Gecko-style adhesion would likely struggle to hold heavy equipment on surfaces like that. Instead, Researchers built MARVEL with electro-permanent magnets in its feet.

Conventional electromagnets drain power continuously to stay on. Electro-permanent magnets work differently. A brief electrical pulse rearranges the internal alignment of the magnet’s poles, switching the grip on or off.

MARVEL’s feet lock and release in about five milliseconds. Once the magnets engage, the wall itself becomes the robot’s ground. Three legs stay anchored while the fourth steps forward. MARVEL travels at 0.7 meters per second on vertical walls and at 0.5 meters per second while