There are a dozen organisms designed by artificial intelligence next to the frog stem cells.
Douglas Blackiston and Sam Kriegman are both related.
Scientists say they've seen a type of replication in organic robots created in the lab using frog cells. The findings could have implications.
A team of researchers from Harvard University, the University of Vermont, and the University of Massachusetts published a paper this week about the discovery of a simple, "programmable" organisms that is created by assembling stem cells in a petri dish.
Douglas Blackiston, a co-author of the study, tells NPR that it's possible to think about using different cells to build blocks.
The researchers hope that one day the same team that published the paper two years ago will be able to reprogram the xenobots to perform useful functions.
The cells from the African clawed frog are used to make the xenobots. The cells aren't genetically modified, but they are combined in different ways to make the xenobots, says Blackiston, a senior scientist at the Allen Discovery Center at Tufts University and the Wyss Institute for Biologically Inspired Engineering at Harvard University.
Stem cells have been compressed into a ball and an artificial intelligence-designed xenobot is sweeping them up.
Douglas Blackiston and Sam Kriegman are both related.
The small hair-like structures known as cilia are used by the xenobots to propel themselves. Blackiston says they have a tendency to spin in a corkscrew fashion, which makes them good for collecting piles of things.
The team used a computer simulation to see how they could manipulate the xenobots into shapes that would be even better at piling things up.
An improved design resulted in an unexpected discovery.
The initial spheroid shape of the xenobots is not the best design for that purpose. The computer suggested a C-shape similar to a snow plow. He says that the shape is very efficient at corralling and collecting stem cells.
The researchers observed that the piles of cells formed copies of the original xenobots, when they were swept up in the dish.
Sexual and asexual reproduction are well known in biology.
Michael Levin is a professor of biology at the Wyss Institute and he says that what the xenobots did is new in living organisms. He says that it does happen at the molecule level, but that there are no organisms that reproduce in this way.
The researchers say it takes about five days to produce a copy. The "offspring" doesn't take on the C-shaped body type of the parent generation, but it does take on the less efficient, original spheroid shape.
There are no brain or suck system in senobots. They can be programmed to do things like corral other cells or do other things. The researchers think of them as tiny organic robots.
The difference between a robot and an organisms is not as sharp as we used to think. "These creatures have both properties."
John von Neumann first suggested the idea of kinematic self-replication in the late 1940s. He wanted machines that could choose from basic robot parts to make copies of themselves.
There's been limited success in making von Neumann machines out of robot parts.
von Neumann machines are easy to make if you just relax the assumption that the robot has to be made out of metal and circuit boards and electronics.
Some scientists have ethical concerns.
Some scientists are concerned about that. The professor of law and philosophy at Duke University was not involved in the research on the ethics of new technologies. "Any time we try to harness life, we should be aware of its potential to go really poorly," she said.
A hypothetical von Neumann machine can't copy itself without raw materials, according to the researchers. There is virtually no chance that they could escape the lab and start reproducing on their own. The researchers only have to remove the inventory of loose stem cells and not make new ones.
Blackiston says that since there's no genetic material coming from the parent, they can't evolve on their own.
He says it would be like finding loose parts of a human and sticking them together to make a copy. It's hard to figure out how evolutionary selection would act on that, because there's nothing transferred between each generation.
The researchers hope that one day the ability to self-replicate could be harnessed for the good of humanity.
Blackiston says that this is a first step, but you could think down the line. "If we could program these better, we might be able to pick up and move specific cell types that we want or help us shape something that we're building in a dish for regenerative medicine."
"This form of replication happens spontaneously" is what is interesting for Kreigman. He says that it doesn't need to be evolved over billions of years.
How long it took for life to evolve on Earth is something we think about. It's a very long story, but here in a dish under the right conditions, we found a completely new form of replication in organisms.
He says that discovering a new form of self-replication shows that life is more expected than unexpected.
