Hmm, that diagram is a little misleading. It's not like the bacteria are processing the images in any way, right?! They are merely detecting light and its direction so they can swim that way. Someone correct me if I'm wrong, I guess, but I'd by extremely surprised if there was any sort of image recognition at the cellular level.
Amazing! This will also refute some creationists and intelligent design arguments that point to the eyeball's complexity as something evolutionists could not well fit into their theories of explain. Now it seems the first step could be made towards his the eyeball may have evolved.
Actually the history of the eye has been farily well understood, and the various stages of its evolution can be seen in animals that exist today. Dawkins explains it: https://www.youtube.com/watch?v=Nwew5gHoh3E
The eye is more advanced but the primary activity of the eye is focusing light and doing something with that focal point.I'm willing to cut the headline some slack for the general publics benefit. This is a legitimately surprising but very sensible result.
To reinforce what you're saying, I just want to point out that the retina is actually a part of the central nervous system. It grows from the same tissue that the brain does during fetal development.
I would compare the kind of "eye" that these bacteria are more to the parietal eye: it detects light to allow movement toward that light (in the Cyanobacteria, to photosynthesize; in primitive animals, likely to find and eat the Cyanobacteria!)
I almost wonder if the genetic code for the parietal eye + pineal gland looks anything like the code for this bacteria's shell. There could be a continuous line of descendence, there.
Actually they do, and beyond that, the retina contains neurons that do the basic processing before travelling down the optic nerve to the brain. The retina is also basically brain tissue and is part of the central nervous system.
Indeed, among other things, they detect edges, movement, and preprocess color from RGB to something conceptually closer to YUV (with color encoded along two contrast axes: red-green and blue-yellow).
No – significant preprocessing of photoreceptor cell signals occurs in the eye, in the retina. The "raw" signals from the three cone types are processed into luminance and two color-opponent channels before being sent to the visual cortex. (While there are around 130 million retinal receptors, there are only approximately 1.2 million axons bundled in the optic nerve.)
This is at most a philosophical difference. I'd say that being able to react to something is already processing it.
Maybe you're falling for the homunculus fallacy in case of humans. But actually there is no little guy watching some screen in our brains, "processing the images".
There's no sharp distinction between reflex-like reactions and "image recognition". It's not even the case that our vision is "full" or "perfect" image processing. There might be all sorts of more complex ways that our vision could work but it doesn't.
If you mean it's misleading because the bacterium doesn't have an inner first-person experience of looking at something, then again this is a philosophical thing, it's not really observable science.
The point you make is an important one...as the article points out, we knew bacteria moved toward light for years...now we know how...
As humans we imagine that we're very efficient processors, and we are...but, much of the time we're very likely just on on "auto-pilot", responding to stimuli...with all the senses...
Example: Say you're driving down the road, feel hungry, and catch a glimpse of Golden Arches ahead...without very much processing at all you pull into a McDonalds and order a meal...birds in the McDonalds parking lot flit around constantly under cars, checking for bits of French fries dropped or discarded...there's not a lot of difference between us and the birds...we're both responding to stimuli in our environment...without much deep thought at all...it keeps us alive...
One of my favorite quotes is one from "The Judge", a character from Cormac McCarthy's novel Blood Meridian...it puts our existence into a unique perspective:
>“The truth about the world, he said, is that anything is possible. Had you not seen it all from birth and thereby bled it of its strangeness it would appear to you for what it is, a hat trick in a medicine show, a fevered dream, a trance bepopulate with chimeras having neither analogue nor precedent, an itinerant carnival, a migratory tentshow whose ultimate destination after many a pitch in many a mudded field is unspeakable and calamitous beyond reckoning."<
Isn't it more a reflex than an interpretation at that level of complexity. I understand your point, the bacteria reacts to a piece of information. But the mapping is so direct .. it's like hairs on cockroach legs, it 'means' nothing to the insect, if someone stimulates it, it runs away, even though it wasn't a threat.
The diagram is definitely misleading, as is some of the article.
There's no high level integration that would allow image recognition, bacteria are AFAIK too simple for that to happen.
They may have a cellular automata-like mechanism to detect where the biggest light source is in case there is more than one, or it is diffuse rather than focused.
One family of single cell eukaryotes has ocelloids[0] reminiscent of vertebrate and mollusc eyes. Provided nuclear genes form networks conceptually identical to neural nets (i.e. brains), one could imagine that these animals have more elaborate image processing, but I don't know if there's any concrete evidence for it.
If you subscribe to the belief that we're basically a bacterial mat of about 37 trillion [1] cells, each extremely large and complex on its own - it's not too large a jump to interpret the eye as being a 1 billion cell "bacterial sub-mat" that does primitive image capture to support the overall bacterial mat.
It could look in multiple directions too. We're talking a world-spanning bacterial community in constant communication with itself. Its images could be quite sophisticated.
If we can figure out some way to capture and transmit what these (and possibly other bacterial species see), we could have trillions of little cameras everywhere, possibly changing everything from medicine (deliver medical payload based of off visual information or image tumor directly without surgery) to biology (pseudo xenobiology studying the underwater volcanic mats of bacteria and algae) to even intelligence gathering (need to spy? Grow some bacteria in an air vent or other convenient area).
I hope that someone is starting to try and capture images from those mini eyeballs, they then become our mini bio-cameras.
"But it's a vital trick for the bacteria. Without sensing light and moving toward it, the organisms wouldn't be able to photosynthesise, which has been crucial to their survival since time immemorial."
Can this be applied somehow to treat bacterial infections?
The diagram showing the DSLR with the image the right way up as opposed to the eyes, is misleading as the camera is also captured upside down and then flipped in software.
I thought it was already established that the genes for photosensitivity led to the formation of eyes in all animals. And that the proposed benefit in the early Earth's oceans was to keep bacteria from frying themselves if they got too close to the surface (due to there being no ozone layer way back then). So, I'm not sure if this is all earth shattering knowledge at this point, but it's still a fun read.
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[ 3.6 ms ] story [ 61.1 ms ] threadI almost wonder if the genetic code for the parietal eye + pineal gland looks anything like the code for this bacteria's shell. There could be a continuous line of descendence, there.
https://en.wikipedia.org/wiki/YUV
Maybe you're falling for the homunculus fallacy in case of humans. But actually there is no little guy watching some screen in our brains, "processing the images".
There's no sharp distinction between reflex-like reactions and "image recognition". It's not even the case that our vision is "full" or "perfect" image processing. There might be all sorts of more complex ways that our vision could work but it doesn't.
If you mean it's misleading because the bacterium doesn't have an inner first-person experience of looking at something, then again this is a philosophical thing, it's not really observable science.
As humans we imagine that we're very efficient processors, and we are...but, much of the time we're very likely just on on "auto-pilot", responding to stimuli...with all the senses...
Example: Say you're driving down the road, feel hungry, and catch a glimpse of Golden Arches ahead...without very much processing at all you pull into a McDonalds and order a meal...birds in the McDonalds parking lot flit around constantly under cars, checking for bits of French fries dropped or discarded...there's not a lot of difference between us and the birds...we're both responding to stimuli in our environment...without much deep thought at all...it keeps us alive...
One of my favorite quotes is one from "The Judge", a character from Cormac McCarthy's novel Blood Meridian...it puts our existence into a unique perspective:
>“The truth about the world, he said, is that anything is possible. Had you not seen it all from birth and thereby bled it of its strangeness it would appear to you for what it is, a hat trick in a medicine show, a fevered dream, a trance bepopulate with chimeras having neither analogue nor precedent, an itinerant carnival, a migratory tentshow whose ultimate destination after many a pitch in many a mudded field is unspeakable and calamitous beyond reckoning."<
There's no high level integration that would allow image recognition, bacteria are AFAIK too simple for that to happen.
They may have a cellular automata-like mechanism to detect where the biggest light source is in case there is more than one, or it is diffuse rather than focused.
One family of single cell eukaryotes has ocelloids[0] reminiscent of vertebrate and mollusc eyes. Provided nuclear genes form networks conceptually identical to neural nets (i.e. brains), one could imagine that these animals have more elaborate image processing, but I don't know if there's any concrete evidence for it.
--
0. https://en.wikipedia.org/wiki/Ocelloid
* Scientists had been looking at bacteria under a microscope for 340 years.
* Just the other day, someone noticed how bacteria focus light.
If you ever think there's nothing interesting left to discover in your field, read this again!
[1] http://www.smithsonianmag.com/smart-news/there-are-372-trill...
I hope that someone is starting to try and capture images from those mini eyeballs, they then become our mini bio-cameras.
Can this be applied somehow to treat bacterial infections?