Katie Hunt – CNN
This article was published by Katie Hunt in CNN:
The US scientists who created the first living robots say the life forms, known as xenobots, can now reproduce — and in a way not seen in plants and animals.
Formed from the stem cells of the African clawed frog (Xenopus laevis) from which it takes its name, xenobots are less than a millimeter (0.04 inches) wide. The tiny blobs were first unveiled in 2020 after experiments showed that they could move, work together in groups and self-heal.
Now the scientists that developed them at the University of Vermont, Tufts University and Harvard University’s Wyss Institute for Biologically Inspired Engineering said they have discovered an entirely new form of biological reproduction different from any animal or plant known to science.
“Frogs have a way of reproducing that they normally use but when you… liberate (the cells) from the rest of the embryo and you give them a chance to figure out how to be in a new environment, not only do they figure out a new way to move, but they also figure out apparently a new way to reproduce.”
Stem cells are unspecialized cells that have the ability to develop into different cell types. To make the xenobots, the researchers scraped living stem cells from frog embryos and left them to incubate. There’s no manipulation of genes involved.
“Most people think of robots as made of metals and ceramics but it’s not so much what a robot is made from but what it does, which is act on its own on behalf of people,” said Josh Bongard, a computer science professor and robotics expert at the University of Vermont and lead author of the study.
Bongard said they found that the xenobots, which were initially sphere-shaped and made from around 3,000 cells, could replicate. But it happened rarely and only in specific circumstances. The xenobots used “kinetic replication” — a process that is known to occur at the molecular level but has never been observed before at the scale of whole cells or organisms, Bongard said.
With the help of artificial intelligence, the researchers then tested billions of body shapes to make the xenobots more effective at this type of replication. The supercomputer came up with a C-shape that resembled Pac-Man, the 1980s video game. They found it was able to find tiny stem cells in a petri dish, gather hundreds of them inside its mouth, and a few days later the bundle of cells became new xenobots.