Computer-designed "xenobots" built from frog cells move, heal and cooperate
An evolutionary algorithm designed body shapes that were then assembled by hand from frog skin and heart-muscle cells, producing millimetre-scale living machines with behaviours no frog has.
What happened
Researchers used an evolutionary algorithm running on a supercomputer to design thousands of candidate body shapes made of two cell types, passive skin cells and contractile heart-muscle cells. The best designs in simulation were then built by hand from cells taken from Xenopus laevis frog embryos. The resulting constructs, under a millimetre across, moved in the directions predicted, pushed small particles around, and healed after being cut.
Why it matters
The work showed that unmodified cells, with no genetic engineering, can be arranged into new functional forms, and that computer design can predict some of their behaviour. It launched the field the authors call synthetic morphology, and it raised the question of how much of an organism's form is set by its genome as opposed to the cells' ability to self-organize.
Caveats
The constructs live only days to weeks, cannot reproduce on their own, and do no practical task yet. Calling them "robots" is a framing choice that some biologists dispute.