When you’re thinking of bacteria, you’re most likely thinking about microscopic creatures living on instinct, feeding and dying without any thought, consciousness, or even senses. And that is mostly true, but as it turns out, they are far more complicated beings than previously thought, as scientists reveal that bacteria are practically single celled eyeballs.
So wait, bacteria can see?
The discovery stems from the collaboration of an international team of researchers, and it finally answers a question that has been baffling the scientific world for over three centuries – How can these microscopic creatures detect sources of light?
It has been known ever since the scientific community started looking at bacteria via a microscope 340 years ago that cyanobacteria were able to detect light. Despite this fact, nobody was able to determine exactly how or why they were able to do so. Until very recently, that is.
As it turns out, the entire body of the bacteria works pretty much like a lens, focusing the light that falls on it, allowing it to perceive light, but not images. After that, pili (tentacle-like appendages) morph out of the bacteria’s body on the side on which the light hits it, attaching themselves to any nearby surfaces and dragging the microscopic Lovecraftian horror towards the light.
More on bacterial sight
Oh, and in case the image of bacteria sprouting tentacles and dragging themselves towards the nearest source of light while using their entire body as makeshift eyeballs wasn’t disturbing enough, here’s a little more food for thought.
First encountered on our planet 2.7 billion years ago, the blue-green algae, as cyanobacteria are also called, are responsible for the Great Oxygenation Event, which sounds pretty awesome if you don’t know that it was also referred to as the planet’s first great extinction. Oh, that and the planet’s first Ice Age.
According to the experts behind the study, the basic physical principle for bacterial sight and human sight are very similar, with the main differences consisting in each species’ biology. We both use a curved surface as a lens in order to focus light.
This is what the team refers to as convergent evolution, which is when two very distant species evolve similar functional techniques to carry out the same task. It’s a surprisingly common trait in nature.
Now that we finally understand exactly how bacteria see after 350 years of investigations, the scientists behind the project hope that they will soon be able to put that into more practical use.
Image source: Wikimedia