The article “The Beautiful Intelligence of Bacteria and Other Microbes” in Quanta Magazine, by John Rennie and Lucy Reading-Ikkanda, is not your typical SETI paper. But maybe studying the behaviour of these “simple” creatures could give us insights about intelligence and anthropocentrism.
The entire point of the article is to explain how some single-celled organisms, individually some of the simplest forms of life, can congregate in biofilms and slime molds that collectively “solv[e] problems and contro[l] their environment” in a form of “cellular intelligence”.
The article is full of beautiful time-lapse photography from the lab of Harvard’s Roberto Kolter. Most SETI papers don’t have such stunning visuals – the “traditional” astrobiologists have us beat there.
Examples of “cellular intelligence” given in the article include mapping terrain, forming complex wrinkled structures to allow all of the individual cells to have access to oxygen (see the .gif above), the differentiation of edge cells to allow “dendritic swarming” (a means of rapid colonization), and self-recognition / elimination of other strains and species near it. This was surprising to me, as it seems somewhat crazy to me that a ton of single-celled organisms have the capability to organize and accomplish such complex tasks. The analogy to artificial intelligence is made in the article, and that’s the best way that I’ve found to think about it: a lot of simple, single lines of code can form something that executes complex and surprising behaviour (ex. neural networks), so it seems reasonable that biology can do the same thing.
The thing that struck me the most, however, was the description of the way that biofilms repel “freeloaders”, discriminate against adjacent colonies that are too genetically divergent, and even stab nearby intruders with the bacterial equivalent of poisoned spears. The article calls the strategy “kin discrimination”. To me, this feels uncomfortably close to some of the less generous aspects of human nature.
And if mats of single-celled organisms, some of the simplest and most primitive life forms on Earth, show these particular characteristics, why should we be surprised if extraterrestrial single-celled organisms show the same characteristics? These same single-celled organisms might share a last common ancestor with the intelligent alien life that we’re looking for with SETI.
Life itself, thorny definitional questions aside, reproduces and metabolizes. And if something is preventing one of those two things, life needs to defend against that, or die. That brutalism, driven by practicality, might not be some base nature of humanity, but a base nature of life itself at the level of single-celled organisms.
Philosophical ramblings aside, the implications for SETI, to me, are pretty clear: should we be surprised if alien life is tribalistic, hostile, territorial, species-ist, and/or altogether terrible? It’s not like humanity, the only intelligent life we know of, has managed to overcome these tendencies yet.
Something to think on, at the very least.