The new weird jerks may seem interesting at first glance because of their resemblance to Pac-Man, but their resemblance to this video game character is probably the least weird thing about them. These unusual robotic creatures are part of what researchers in a new study showed last year: robots that, for the first time in the world, were built entirely using living cells. “These are new living machines,” explained Joshua Bongard, a computer and robotics scientist at the University of Vermont at the time.
Now Bongard and his colleagues have entered the next stage, giving honeybees the ability to reproduce and create new versions of themselves. In this case, self-replication is not achieved by the kind of reproductive techniques we usually see in normal living organisms.
The researchers found that if they placed a sufficient number of honeycombs adjacent to each other in a laboratory container, their collective motion would bring together the free cells of the frog floating in solution.
When enough of those cells are put together, a mass of about 50 cells naturally becomes the offspring of honeycombs that can swim independently and create their own offspring.
This phenomenon, called spontaneous kinetic or kinematic replication, has previously been seen in other types of molecular models and machines, but has not been observed in multicellular living systems such as honeycombs. Researchers in a new article explaining these recyclable creatures say:
We found that kinetic multicellular assemblies can also create functional versions of themselves by moving and compressing free cells in their environment. This form of immortality, which has never been seen before in any organism, occurs spontaneously within a few days; Not to evolve over thousands of years.
Simulation (left) predicts true self-replicating system (right) in vitro
Researchers to build self-replicating robots, pluripotent stem cells of the African toad’s embryonic skin (Xenopus laevis) And placed them in saline solution. During this process, a number of cells clumped together into a spherical creature, and cilia formed on its outer surface that allowed it to move.
When the twelve first-generation organisms were transferred to another container with free stem cells, the movement of these organisms brought the free stem cells together into masses that formed a new generation of organisms that repeated the same behavior. However, when the same stem cells were left alone in solution, they did not clump together. This shows that the initial movement of the ancestral knees is needed to create the next generation.
The researchers explained in their paper that this self-replicating movement behavior, which is a behavior not previously seen in plants or animals, can be achieved without genetic modification. This shows how biological molecules can adapt and change in response to their environment.
Color image of honeycombs (red) and freedom stem cells stacked together (green)
Using artificial intelligence to simulate conditions that may increase self-replicating behaviors, the researchers found that they could amplify the phenomenon. They explain:
Simulations showed that some shapes enhanced mass size and reproduction cycles, while others reduced it or prevented self-replication. Some geometric shapes, but not all, were better than spherical shapes.
Ultimately, these circular shapes (essentially three-dimensionally packed) were the best candidate for the frog’s free cells to accumulate in the form of new organisms, and changes in the environment (walls that restricted the movement of honeycombs) also contributed to this process.
While we are still in the early stages of working with living robots, researchers say that if we can figure out how they work and find the right task for them, unusual creatures can one day do useful things. “These entities may help improve future technologies and reduce the need for outside guidance,” the researchers explain. “Life is full of amazing behaviors beyond what we see, waiting to be discovered.”
The findings are reported in the journal PNAS.