Chamadas de biobots, esses organismos consistem em uma terceira forma de vida, já que não são, especificamente, robôs e nem seres vivos. É uma mistura dos dois, feita de células da pele e do coração de sapos, e programada por computador. UM CANCERIANO SEM LAR.
A invenção dessas “máquinas viventes”, elaboradas com células animais e capazes de realizar pequenas tarefas, é de quatro cientistas norte-americanos, composto por dois biólogos, Michael Levin e Douglas Blackiston, e dois especialistas do campo da robótica, Josh Bongard e Sam Kriegman.
Em artigo publicado na revista PNAS, o grupo de pesquisadores descreve a criação desse tipo de biobots, os xenobots (as células são da espécie de sapo Xenopus laevis) — com a ajuda de algoritmos evolutivos.
Os pesquisadores utilizaram como matéria-prima dois tipos de células de rã-de-unhas-africana: as células de seu coração (contráteis) e as de sua pele (mais passivas). O principal resultado é uma máquina biológica de meio milímetro, com poucas centenas de células, capaz de se mover em uma direção determinada pelos cientistas. El País
“A grande pergunta aqui é: como as células cooperam para construir corpos complexos e funcionais? Como sabem o que precisam construir? Que sinais trocam entre elas?”, reflete Levin, da Universidade Tufts, perto de Boston. UM CANCERIANO SEM LAR.
“Se conseguirmos automatizar a fabricação dos modelos por computador, poderemos conceber enormes enxames de biobots. E eles poderiam até mesmo ser capazes de se juntar em tamanhos cada vez maiores. Poderemos ter biomáquinas enormes no futuro”, coloca como hipótese Bongard. Sua equipe já fez simulações de até 270.000 células. Um corpo humano tem 30 trilhões.
Will self-replicating ‘xenobots’ cure diseases, yield new bioweapons, or simply turn the whole world into grey goo? Australasian Science
In 2020, scientists made global headlines by creating “xenobots” – tiny “programmable” living things made of several thousand frog stem cells. Early xenobots survived for up to ten days.
A second wave of xenobots, created in early 2021, showed unexpected new properties. These included self-healing and longer life. They also showed a capacity to cooperate in swarms, for example by massing into groups.
The same team of biology, robotics and computer scientists unveiled a new kind of xenobot. Like previous xenobots, they were created using artificial intelligence to virtually test billions of prototypes, sidestepping the lengthy trial-and-error process in the lab. But the latest xenobots have a crucial difference: this time, they can self-replicate.
But they don’t reproduce in a traditional biological sense. Instead, they fashion the groups of frog cells into the right shape, using their “mouths”. Ironically, the recently extinct Australian gastric-brooding frog uniquely gave birth to babies through its mouth.
The latest advance brings scientists a step closer to creating organisms that can self-replicate indefinitely. Is this as much of a Pandora’s Box as it sounds?
Conceptually, human-designed self-replication is not new. In 1966, the influential mathematician John Von Neumann discussed “self-reproducing automata”.
Famously, Eric Drexler, the US engineer credited with founding the field of “nanotechnology”, referred to the potential of “grey goo” in his 1986 book Engines of Creation. He envisaged nanobots that replicated incessantly and devoured their surroundings, transforming everything into a sludge made of themselves.
In 2002, without the help of AI, an artificial polio virus created from tailor-made DNA sequences became capable of self-replication. Although the synthetic virus was confined to a lab, it was able to infect and kill mice.
It might be natural to have instinctive reservations about xenobot research. One xenobot researcher said there is a “moral imperative” to study these self-replicating systems, yet the research team also recognises legal and ethical concerns with their work.
Centuries ago, English philosopher Francis Bacon raised the idea that some research is too dangerous to do. While we don’t believe that’s the case for current xenobots, it may be so for future developments.
Any hostile use of xenobots, or the use of AI to design DNA sequences that would give rise to deliberately dangerous synthetic organisms, is banned by the United Nations’ Biological Weapons Convention and the 1925 Geneva Protocol and Chemical Weapons Convention.
However, the use of these creations outside of warfare is less clearly regulated.
The interdisciplinary nature of these advances, including AI, robotics and biology, makes them hard to regulate. But it is still important to consider potentially dangerous uses.
Although xenobots are not currently made from human embryos or stem cells, it is conceivable they could be. Still, as the researchers say, living matter can behave in unforeseen ways, and these will not necessarily be benign.
Previous version: Biobots
Other bits: Primeiros robôs ‘vivos, os xenobots, agora podem se reproduzir, A little robot: Edição on line – Ao vivo (entenda o raciocinio)