Endosymbiosis. Bacteria rock.
Bacteria gettin' it on
There's nothing in the title of this post that says "read me", I know. But endosymbiosis is maybe the most amazing thing that nobody ever gets taught. Much. Or maybe they do now, they didn't when I went to school and uni.
The word 'symbiosis' isn't that unknown though. Or symbiotic. You hear it a lot in business, for example. People look for symbiosis when they're combining things, finding a way to get two or more different things to work together to produce something that is maybe surprising and creative, and different to the originals. Like a computer company working together with computer chip companies, display companies, marketing companies, etc. They all still stay distinct, but together they make something that's a symbiotic relationship between them.
Endosymbiosis is symbiosis on steroids. It's one of the main ways life itself came to be. Bacteria are masters at it, and when you study what it is they do it really is stranger than fiction. (It turns out all life is bacteria, including us, in case you were starting to nod off.) Bacteria are a bit on the nose reputation-wise, we tend to think of them as evil little creatures who cause disease. But what scientists such as Lynn Margulis have pieced together over the last few decades, and more, is that bacteria are the basic building blocks of life. Life on Earth began as bacteria billions of years ago, and all life since still is bacteria. They created (and still create) the oxygen in our atmosphere, which also created all of the various oxide and other minerals/rocks. And much, much more.
Me or you or a giraffe or a tree don't look much like bacteria, to be sure, but that's where endosymbiosis comes in.
Bacteria live to form symbiotic relationships with other bacteria. They love nothing more than to find another bacterium and to swap properties. They do this in a range of bizarre ways. Sometimes they eat other bacteria, and the bacteria they've eaten continue to live inside them, adding whatever function they had to the body of the eating bacterium. It's exactly as if you could eat a torch and take on the ability to shine light out your eyes. That is literally what bacteria do, every day of the week.
They swap genes too, in what's called horizontal gene transfer. A fancy name, but all it means is that instead, of, like us, having to wait for another generation to be born to mix genes and pass them on to our offspring, so we see new characteristics, they can do this within a single generation. To use an analogy, it's exactly as if we could go and meet a tall person, and then a person with green eyes, and one with blonde hair, and take their tallness, green eyes and blonde hair with us after we've met. That's what bacteria do. They mutate all the time, in real time.
Bacteria can be killed by bad environmental conditions. But if those conditions are OK they never die. Bacteria are immortal. (They're pretty friggin' amazing, hope you're getting that idea.) The stromatolites off the coast of Western Australia are over 3 billion years old.
To get onto how animals such as ourselves are bacteria, humans, as well as all other living things on the planet like plants and fungi, are just colonies of symbiotic bacteria. Our cells and the organs they go on to make all evolved from bacteria working together with other bacteria, sharing and swapping properties and gradually building up bigger living creatures. For example when you get short of oxygen, such as when you've done some very hard exercise, anaerobic (i.e. no-oxygen) respiration processes kick in within your body to keep you going. These processes actually came from anaerobic bacteria, which formed symbiotic relationships with other parts of us as we evolved. The bacteria are all still there, working away symbiotically.
It's not hard to see how all the apparently 'bad' things about bacteria come from the amazing abilities they have. Bacterial diseases like colds and flu, and viruses (which are actually small chunks of bacteria which bacteria use to help swap genes between themselves) are just bacteria doing what they've always done - swapping and sharing bits and pieces of themselves to build new types of life. We thought we were a bit clever inventing antibiotics, and we were, but the 'diseases' we rightly were trying to understand and treat were really only life doing what it's always done, breaking up old patterns and building new ones.
Our bacteria and those outside us have never stopped working together symbiotically to build new forms of life. That's one of the main ways we evolve. It seems bad to us, it makes us 'sick', but that's only because we're mortal. The bacteria that build us are immortal and will kill us along the way to inventing ever new forms of life. To them there is no life versus death, us dying is just another step along the way of them symbiotically weaving together new forms of life.
So bacteria totally rock, they don't deserve the bad press they get. We won't ever 'beat' them with anti-biotics or antiseptics, because we ARE bacteria and ultimately we're just beating up on ourselves. The new 'superbugs' evolving that are resistant to all anti-biotics are proof of that. The theory of evolution was for a long time hijacked by the 'survival of the fittest' people who saw all evolution as competition and fighting. But really the engine room of evolution has been symbiosis, and it still is today. It's what allows hugely different and novel things to emerge within a single generation, and the 'fittest' are then selected from these amazingly weird, new hybrid beings.
We need to find ways to work together with bacteria, because again that's what we are. To find ways to harness the endless creative ability of bacteria to design new ways to respond to the world around us. That's what they've always done, and what they always will do, and if we stop fighting them and work with them, the sky's the limit.
(I'd highly recommend Lynn Margulis' "What is Life" if you're interested in endosymbiosis.)