Reading eminent biologist Lynn Margulis, who was married to Carl Sagan, you experience a disturbing as well as fascinating vertigo. It’s inevitable to be filled with amazement at discovering that free bacteria that lived two thousand million years ago seem to be the ancestors of all our cells, that other independent photosynthetic bacteria dating back several hundred million years could be the ancestors of mitochondria hosted within our cellular bricks (as well as of chloroplasts within plant cells) and that spirochetes (bacteria with flagellum) could be at the origin of all our muscle cells, sperm cells and neurons.
This goes far beyond that noting that our six-million-year-old grandparents are the same as those of current chimpanzees, that 60-million-year-old ones are the same as those of current lemurs, or that 600-million-year-old ones are the same as those of current plants and fungi. It’s a remote as well as intimate connection with a microscopic world that not only allows us to exist but it is also an active part of our life (I mean our own body, because symbiotic bacteria dwelling inside us – for example, in the large intestine- are an interesting chapter apart).
Human thoughts and feelings would therefore be the product of a neural network of bacterial origin (some scientific studies include symbiotic intestinal bacteria in the factory of our psyche, as they influence our state of mind), so the basic principles of functioning of human mind (of any animal intelligence) might not be very different from those of a bacterial community developed in a rotten apple or in a Petri dish in a laboratory. One difference is the type of information collected and processed by the network: for bacterial communities and plants, only chemical signals (pheromones) or electrical ones, and environmental rudimentary data (acidity, humidity, temperature, light, etc.); for animals, much more profuse sensory data with which to build vision, hearing, smell, taste, touch, social intelligence… Another difference is a centralized model in our case (with brain as a control center) and a decentralized one for bacteria and plants. Of course, the most important thing is network’s level of complexity (the number of connections between our neurons is gigantic, which allows us to study stuff such as black holes or gravitational waves).
Science already tells us that language is not necessary to have a rational thought: human and non-human animals act rationally (for all our sakes, since natural selection is usually implacable) and sometimes also irrationally (in the same way that humans have religions, non-human also exhibit superstitious and absurd practices as long as they are functional -religion has been- or at least not dysfunctional for survival). What if bacteria also lead themselves rationally, like sort of computers that, according to a particular program, generate outputs from a series of inputs?… What if the whole biosphere (identified with self-regulated Lovelock’s Gaia) was a rational agent?… What if bacteria and Gaia could also behave irrationally?…