Dec 12, 2023
“I’ll bet a bacterium could hold its own in any Parisian café. They don’t need to study existentialism at the Sorbonne; they live it every day.”
“If I only had a brain,” intones Scarecrow in The Wizard of Oz. Of course, it turns out that Scarecrow already had a brain…or didn’t need one. Same for bacteria!
These unicellular organisms first appeared on Earth about 4 billion years ago. Today, they cover the planet and fill nearly every ecological niche. All life on Earth is either bacterial or evolved from bacteria. These unicellular organisms survive, or can quickly evolve to survive, in almost any environment, no matter how hostile. Like us, they can even alter their environment to make it more habitable.
Originally anaerobic on an oxygen-poor planet, prokaryotic (no nucleus) bacteria merged to form the first eukaryotic cells (with nucleus) which in turn formed plants that produced the oxygen that bacteria later learned to breathe. Wrap your noodle around that one! But before there was sufficient atmospheric oxygen, bacteria used iron to power its cellular processes. “If I don’t have blue, I use red.” (Picasso)
Bacteria are as close as nature has come to creating a ‘quantum of life’, i.e., the minimal configuration of molecules required to support phenomena we recognize as ‘living’. No surprise then that we view bacteria as irremediably stupid. “Dumb as dirt!” Of course…they are dirt!
But how is it then that bacteria compete with us and certain insects for dominion over Earth? Like Scarecrow, they have no organelle that performs the functions we associate with a ‘brain," but like Scarecrow, they apparently don’t need one. They have devised other ways to ‘think’.
Everything wants to think. Sum ergo Cogito (I am; therefore, I think). But thinking does not require neurons; it can happen using a multitude of physical pathways. If things want to think, they’ll find a way to do so. Bacteria don’t need brains to think, just as they don’t need sex to reproduce. They freely swap genes with one another; no ‘dinner and a movie’ required.
People say that Anarchism is an impractical political ideology. For all its theoretical appeal, it simply won’t work. Really? Bacterial society is paradigmatically anarchic, and it’s worked for 4 billion years. There’s no whiff of authority. Like unsupervised kids on a 1950s playground, bacteria work stuff out…by themselves.
For 200 years, from 1250 to 1050 BCE, “Israel had no king; everyone did what was right in their own eyes.” (Judges 21: 25) When circumstances required a coordinated response, charismatic leaders called ‘judges’ emerged ad hoc, and with the consent of the elders and the people, they provided the temporary leadership needed to address the immediate challenge…and then they returned home to tend their flocks. But Israel succumbed to the siren song of authoritarianism. They wanted to be ‘like other nations’. They wanted a king…and they got one: How did that work out for them?
So, how do bacteria think? We still have a lot to learn, but scientists have just discovered that bacteria can create memories by regulating the amount of iron in their systems. Researchers at The University of Texas at Austin found that bacteria use iron levels to store information about different behaviors that can then be activated in response to certain stimuli. “Bacteria don’t have brains, but they can gather information from their environment, and…they can store that information and quickly access it later for their benefit,” said Souvik Bhattacharyya.
Most intriguingly, bacteria pass along that information to their progeny, down at least to the fourth generation. Humans pass along information in two ways: long-term via genes and short-term via culture. Bacteria have it the other way around. They modify their genes on an almost daily basis, but their ‘culture’ preserves memories for at least four generations. And we struggle to pass info down just one generation…to our children. Bottom line, on any ‘species neutral’ AP History exam, my money’s on the bacterium.
Single, free-floating bacteria have naturally varying levels of iron. Bacterial cells with lower levels of iron tend to swarm, while the bacteria that form biofilms have higher iron levels. You may be forgiven for thinking that cells with low iron gravitate toward ‘swarming’ while their high iron cousins prefer ‘filming’; after all, you think that smarter people become doctors while less smart people work at McDonald’s. But you’re wrong…on all counts!
Any bacterium can swarm or film; it just needs to ‘decide’ what it wants to do and adjust its iron content accordingly. When iron levels are low, bacteria form fast-moving swarms to search for new sources of iron. When iron levels are higher, bacteria are more likely to feel satisfied, so they stay put and form films.
“I know who I am, and I know that I can be whoever I want to be.” I’ll bet a bacterium could hold its own in any Parisian café. They don’t need to study Existentialism at the Sorbonne; they live it every day. So hats off to our bacterial cousins… and don’t forget, they are people too.