17 ms·

Single-Celled Organism Appears to Make Decisions (2019)

113 points by jwmhjwmh 6y ago

wombatmobile 6y ago
So, a scientist tried to replicate an experiment and failed, then kept trying until he succeeded by changing one factor of the experiment - the stimulus. To Fix the Reproducibility Crisis, Rethink How We Do Experiments https://blogs.scientificamerican.com/observations/to-fix-the-reproducibility-crisis-rethink-how-we-do-experiments/ https://blogs.scientificamerican.com/observations/to-fix-the...
- dharmab 6y ago
  “So an inventor tried to make a lightbulb and failed, then kept trying until he succeeded by changing one factor - the filament.” The paper also includes dozens of trials replicating the results across organisms.
  - wombatmobile 6y ago
    Well, I think it is an important result. If single celled organisms make decisions, what does that tell us about volition? Evidence of volition and decision making in this form simplifies the challenge of understanding "consciousness".
    - JumpCrisscross 6y ago
      > If single celled organisms make decisions, what does that tell us about volition? Not much. The organism is expressing a preference for staying alive. That is a default preference for life. The question of volition only emerges with higher preferences or ones at odds with survival.
    - visarga 6y ago
      > If single celled organisms make decisions, what does that tell us about volition? The cell is a mechanism tested and refined by evolution. It's purpose is to sustain itself, adapt to the environmental aggressions and self replicate. Its volition is the best strategy nature could find to keep it alive.
      - wombatmobile 6y ago
        Yeah, I'm wondering if or why we should consider volition in multi-cellular organisms any differently? Are not single celled organisms as "conscious" as multi-celled organisms? Or, alternatively, are multi-celled organisms not as non-"conscious" as single celled organisms?
        visarga 6y ago
        Even if a cell is so different in complexity to an organism, they both solve the same problem - what action should I take now, given the state of the environment and previous experience.
        wombatmobile 6y ago
        What is your understanding of the term "consciousness"? What organism/s experience it?
nickpeterson 6y ago
I don't understand the issue? Decisions are just a state machine getting different inputs. It's the same for trees and humans.
- jwmhjwmh 6y ago
  The article says the organism tries several approaches in succession to escape the unpleasant carmine. This still isn't super advanced behavior, but it's interesting considering the organism is single-celled.
  - JumpCrisscross 6y ago
    > the organism tries several approaches in succession to escape the unpleasant carmine This implies memory. Venus fly traps use calcium gradients for short-term memory [1]. It would be interesting to learn how this organism remembers. [1] https://www.sciencenews.org/article/how-venus-flytraps-store-short-term-memories-prey https://www.sciencenews.org/article/how-venus-flytraps-store...
    - im3w1l 6y ago
      > This implies memory. Shouldn't be too surprising. "In genetics, a promoter is a sequence of DNA to which proteins bind that initiate transcription of a single RNA from the DNA downstream of it. This RNA may encode a protein, or can have a function in and of itself, such as tRNA, mRNA, or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand)." In programming terminology, the promoter region listens for events, and is followed by a handler body. So protein concentrations can be used for state. Regarding the calcium gradients you mentioned, I wonder... I think they are more about inter-cellular communication. Cells can use calcium to make electricity. Calcium is also used by neurons to send electric pulses. I actually find it fascinating that neurons are not unique in using electricity to communicate - that an analog exists in the plant world.
    - LaserPineapple 6y ago
      What does it remember? The approach tried previously?
olvar_ 6y ago
impressive, I know many (allegedly) brained organisms capable of much less.
ta1234567890 6y ago
From 2016: "How Slime Molds make decisions" https://www.scientificamerican.com/video/how-slime-molds-make-decisions/ https://www.scientificamerican.com/video/how-slime-molds-mak...
nobodyandproud 6y ago
Perhaps the least relevant, but I really enjoyed the moral outrage portion of the renewed study.
obiefernandez 6y ago
I think they buried the lede, which is that it has implications for the evolution of brains “This paper nicely settles a debate between those [researchers] willing to accept that non-neuronal organisms are also capable of processing information and acting on that information, and those that stick to the idea that only neuronal organisms are capable of complex decision making,” Madeleine Beekman, an evolutionary ecologist at the University of Sydney who was not involved in the study, writes in an email to The Scientist. “Clearly there is a fundamental difference between brained and brainless organisms,” she continues, “[b]ut the point is that a brain did not come out of nothing. The brain is the result of selection pressure placed on organisms with the most basic form of information processing. Gunawardena and colleagues show that this basic ground work is already present in unicellular organisms.”
- busyant 6y ago
  > This paper nicely settles a debate between those [researchers] willing to accept that non-neuronal organisms are also capable of processing information and acting on that information, and those that stick to the idea that only neuronal organisms are capable of complex decision making,” Madeleine Beekman ... writes .... I don't know who Dr. Beekman has been debating with, but, at best, this has only been a debate of semantics for at least 50 years. Here is an excerpt from a review titled Bacterial Microprocessing (Cold Spring Harb Symp Quant Biol. 1990;55:539-45. doi: 10.1101/sqb.1990.055.01.052.). The review is from 1990, but the work goes back at least to the late 1960s. To someone trying to understand the brain, the bacterium Escherichia coli must be an awesome beast. Its talents are legion, but its size is miniscule. E. coli is a cylindrical organism less than 1 μm in diameter by 2/μm long--20 would fit end-to-end in a single rod cell of the human retina or some 3000 in that of a frog. Yet, it is adept at counting molecules of specific sugars, amino acids, or dipeptides; at integration of similar or dissimilar sensory inputs over space and time; at comparing counts taken over the recent and the not so recent past; at triggering an all-or-nothing response; at swimming in a viscous medium; and as we shall see, even at pattern formation. At the 53rd Symposium, I presented an overview of sensory transduction in bacterial chemotaxis (Berg 1988), describing the kinds of measurements that E. coli makes on its surroundings and noting how this strategy matches the physical constraints imposed by small size in an aqueous environment (i.e., by life at low Reynolds number; see Purcell 1977). I will restate that case briefly, comment on progress made in the field during the past 2 years, and mention some of the work going on in my own laboratory.
adamjb 6y ago
"Cognition all the way down: Biology’s next great horizon is to understand cells, tissues and organisms as agents with agendas (even if unthinking ones)" https://aeon.co/essays/how-to-understand-cells-tissues-and-organisms-as-agents-with-agendas https://aeon.co/essays/how-to-understand-cells-tissues-and-o...
radford-neal 6y ago
It's not noted in the article, but it may be important that Stentor is a ciliate (same group as paramecium). Ciliates are very elaborate single-celled organisms, with the unusual feature of having a "macronucleus" in addition to a "micronucleus" that is similar to the single nucleus of other eukaryote cells. The macronucleus contains numerous copies of DNA from the micronucleus, which could provide a lot of scope for states that are represented in terms of gene activations, allowing behaviours such as described in the article.
- ncmncm 6y ago
  This is new to me. This specializes the regular nucleus for reproduction, while the macronucleus becomes a sort of brain, using DNA as an information processing and storage engine? It calls attention to the brain-like activity of the regular nucleus in cells that don't have a macronucleus, and of the raw DNA in a bacterium.
ada1981 6y ago
And 4 years ago they even won the electoral college!
arnoooooo 6y ago
This reminds me of Donald Hoffman's theory of conscious agents. He posits the simplest conscious agent to be a binary one : it can make only one kind of decision, with only two possibilities.
- OnACoffeeBreak 6y ago
  Here is a discussion between Donald Hoffman, Sam Harris and Annaka Harris about Hoffman's ideas on consciousness: https://samharris.org/podcasts/178-reality-illusion/ https://samharris.org/podcasts/178-reality-illusion/
im3w1l 6y ago
Ok so cells make decisions. But what about organelles with independent dna - what about mitochondria and plastids?
- Retric 6y ago
  Yes, though the details vary quite a bit. https://en.wikipedia.org/wiki/Regulation_of_gene_expression https://en.wikipedia.org/wiki/Regulation_of_gene_expression
dr_dshiv 6y ago
So an individual person is extremely complex -- so a simple storefront business could easily be simpler than a person. Similarly, a single cell is incredibly complex -- so a simple multicellular organism (like a worm) could easily be simpler than a cell. We all began as single cells (zygotes) and somewhere along the way we suddenly became conscious, whereas a moment before, we were not conscious. What was that point in time?
- gameshot911 6y ago
  >We all began as single cells (zygotes) and somewhere along the way we suddenly became conscious, whereas a moment before, we were not conscious. You may not have realized it, but many would debate the assumptions in that sentence. ^_^ Sidestepping a decent into the definition of 'conscious' itself for now, one could propose that consciousness is an inherent nature of matter itself, and it just emerges further/grows in complexity as the zygote develops.
  - visarga 6y ago
    A more justified explanation would be that consciousness is the capacity to learn and adapt to the environment, so we don't have to say 'it just emerges'. It's there, even at cell level, but it's not inherent in matter, that makes no sense. It's probably inherent in self replicators that live in a competitive environment, but not just any matter. Rocks don't learn and adapt and have no reason to do so.
  - mensetmanusman 6y ago
    Is there evidence of humans that skip the zygote phase of life?
    - dr_dshiv 6y ago
      lol, no -- but one could imagine splitting up stem cells to grow new humans
  - ncmncm 6y ago
    Since "conscious" is an aggressively undefined term, you can say anything about it that feels good. I say "aggressively" because any attempt at a precise operational definition brings random testy objections out of the woodwork, typically invoking varying degrees of woo. Ultimately, nobody has determined a practical need for a definition, or really for the word, outside of discussion of people in comas, so reasonable people let it go.
robotresearcher 6y ago
'Makes decisions' is a terrible headline for this story. A thermostat makes decisions. 'Makes a suprisingly sophisticated series of decisions' is more supportable. But whether you are surprised depends on your intuition about how complex a tiny machine with feedback from sensors and quite a lot of internal state can be. Since almost every biological system I've ever learned anything about is mind-bogglingly rich with complex dynamics, my default is to be unsurprised by rich externally-observable behavior.
- eli_gottlieb 6y ago
  > 'Makes decisions' is a terrible headline for this story. A thermostat makes decisions. Well yes, that's the point. They found that prospective control goes faaaaaaaaaar back in evolutionary history.
typedef_struct 6y ago
Serious question: if I reframe the carnot heat engine as a decision making process that heat undergoes, can I publish a biology paper on it?
TaupeRanger 6y ago
It's all about oscillatory patterns. These occur in all living things, it's just that brains are especially good at creating and maintaining them.
musicale 6y ago
Appropriate for the election.
sodii 6y ago
Biochemical signal transduction networks, consisting of receptors and enzymes, are very similar to artificial neural networks, in terms of computational structure.
zalkota 6y ago
I enjoy the theory that microtubules contain mini quantum computers that derive consciousness.
FerretFred 6y ago
Great! Maybe we (Britain) can appoint it as Prime Minister in the next election. Gotta be better than what we have now.
ncmncm 6y ago
This seems an appropriate topic in connection with the recent posting[0] about Charles Turner. I hope his work appears in the reference list, alongside the Harvard eugenicist. I know which neglected body of work I think is the more significant. [0] https://news.ycombinator.com/item?id=24949335 https://news.ycombinator.com/item?id=24949335
juancn 6y ago
I don’t get what’s surprising. DNA transcription is computation. Decision making only needs the most basic of conditional information processing. Pretty much any regulatory process leading to homeostasis is a form of decision making.

113 points by jwmhjwmh 6y ago

So, a scientist tried to replicate an experiment and failed, then kept trying until he succeeded by changing one factor of the experiment - the stimulus. To Fix the Reproducibility Crisis, Rethink How We Do Experiments https://blogs.scientificamerican.com/observations/to-fix-the-reproducibility-crisis-rethink-how-we-do-experiments/ https://blogs.scientificamerican.com/observations/to-fix-the...

dharmab 6y ago
“So an inventor tried to make a lightbulb and failed, then kept trying until he succeeded by changing one factor - the filament.” The paper also includes dozens of trials replicating the results across organisms.
- wombatmobile 6y ago
  Well, I think it is an important result. If single celled organisms make decisions, what does that tell us about volition? Evidence of volition and decision making in this form simplifies the challenge of understanding "consciousness".
  - JumpCrisscross 6y ago
    > If single celled organisms make decisions, what does that tell us about volition? Not much. The organism is expressing a preference for staying alive. That is a default preference for life. The question of volition only emerges with higher preferences or ones at odds with survival.
  - visarga 6y ago
    > If single celled organisms make decisions, what does that tell us about volition? The cell is a mechanism tested and refined by evolution. It's purpose is to sustain itself, adapt to the environmental aggressions and self replicate. Its volition is the best strategy nature could find to keep it alive.
    - wombatmobile 6y ago
      Yeah, I'm wondering if or why we should consider volition in multi-cellular organisms any differently? Are not single celled organisms as "conscious" as multi-celled organisms? Or, alternatively, are multi-celled organisms not as non-"conscious" as single celled organisms?
      - visarga 6y ago
        Even if a cell is so different in complexity to an organism, they both solve the same problem - what action should I take now, given the state of the environment and previous experience.
        wombatmobile 6y ago
        What is your understanding of the term "consciousness"? What organism/s experience it?

nickpeterson 6y ago

I don't understand the issue? Decisions are just a state machine getting different inputs. It's the same for trees and humans.

jwmhjwmh 6y ago
The article says the organism tries several approaches in succession to escape the unpleasant carmine. This still isn't super advanced behavior, but it's interesting considering the organism is single-celled.
- JumpCrisscross 6y ago
  > the organism tries several approaches in succession to escape the unpleasant carmine This implies memory. Venus fly traps use calcium gradients for short-term memory [1]. It would be interesting to learn how this organism remembers. [1] https://www.sciencenews.org/article/how-venus-flytraps-store-short-term-memories-prey https://www.sciencenews.org/article/how-venus-flytraps-store...
  - im3w1l 6y ago
    > This implies memory. Shouldn't be too surprising. "In genetics, a promoter is a sequence of DNA to which proteins bind that initiate transcription of a single RNA from the DNA downstream of it. This RNA may encode a protein, or can have a function in and of itself, such as tRNA, mRNA, or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand)." In programming terminology, the promoter region listens for events, and is followed by a handler body. So protein concentrations can be used for state. Regarding the calcium gradients you mentioned, I wonder... I think they are more about inter-cellular communication. Cells can use calcium to make electricity. Calcium is also used by neurons to send electric pulses. I actually find it fascinating that neurons are not unique in using electricity to communicate - that an analog exists in the plant world.
  - LaserPineapple 6y ago
    What does it remember? The approach tried previously?

olvar_ 6y ago

impressive, I know many (allegedly) brained organisms capable of much less.

ta1234567890 6y ago

From 2016: "How Slime Molds make decisions" https://www.scientificamerican.com/video/how-slime-molds-make-decisions/ https://www.scientificamerican.com/video/how-slime-molds-mak...

nobodyandproud 6y ago

Perhaps the least relevant, but I really enjoyed the moral outrage portion of the renewed study.

obiefernandez 6y ago

I think they buried the lede, which is that it has implications for the evolution of brains “This paper nicely settles a debate between those [researchers] willing to accept that non-neuronal organisms are also capable of processing information and acting on that information, and those that stick to the idea that only neuronal organisms are capable of complex decision making,” Madeleine Beekman, an evolutionary ecologist at the University of Sydney who was not involved in the study, writes in an email to The Scientist. “Clearly there is a fundamental difference between brained and brainless organisms,” she continues, “[b]ut the point is that a brain did not come out of nothing. The brain is the result of selection pressure placed on organisms with the most basic form of information processing. Gunawardena and colleagues show that this basic ground work is already present in unicellular organisms.”

busyant 6y ago
> This paper nicely settles a debate between those [researchers] willing to accept that non-neuronal organisms are also capable of processing information and acting on that information, and those that stick to the idea that only neuronal organisms are capable of complex decision making,” Madeleine Beekman ... writes .... I don't know who Dr. Beekman has been debating with, but, at best, this has only been a debate of semantics for at least 50 years. Here is an excerpt from a review titled Bacterial Microprocessing (Cold Spring Harb Symp Quant Biol. 1990;55:539-45. doi: 10.1101/sqb.1990.055.01.052.). The review is from 1990, but the work goes back at least to the late 1960s. To someone trying to understand the brain, the bacterium Escherichia coli must be an awesome beast. Its talents are legion, but its size is miniscule. E. coli is a cylindrical organism less than 1 μm in diameter by 2/μm long--20 would fit end-to-end in a single rod cell of the human retina or some 3000 in that of a frog. Yet, it is adept at counting molecules of specific sugars, amino acids, or dipeptides; at integration of similar or dissimilar sensory inputs over space and time; at comparing counts taken over the recent and the not so recent past; at triggering an all-or-nothing response; at swimming in a viscous medium; and as we shall see, even at pattern formation. At the 53rd Symposium, I presented an overview of sensory transduction in bacterial chemotaxis (Berg 1988), describing the kinds of measurements that E. coli makes on its surroundings and noting how this strategy matches the physical constraints imposed by small size in an aqueous environment (i.e., by life at low Reynolds number; see Purcell 1977). I will restate that case briefly, comment on progress made in the field during the past 2 years, and mention some of the work going on in my own laboratory.

adamjb 6y ago

"Cognition all the way down: Biology’s next great horizon is to understand cells, tissues and organisms as agents with agendas (even if unthinking ones)" https://aeon.co/essays/how-to-understand-cells-tissues-and-organisms-as-agents-with-agendas https://aeon.co/essays/how-to-understand-cells-tissues-and-o...

radford-neal 6y ago

It's not noted in the article, but it may be important that Stentor is a ciliate (same group as paramecium). Ciliates are very elaborate single-celled organisms, with the unusual feature of having a "macronucleus" in addition to a "micronucleus" that is similar to the single nucleus of other eukaryote cells. The macronucleus contains numerous copies of DNA from the micronucleus, which could provide a lot of scope for states that are represented in terms of gene activations, allowing behaviours such as described in the article.

ncmncm 6y ago
This is new to me. This specializes the regular nucleus for reproduction, while the macronucleus becomes a sort of brain, using DNA as an information processing and storage engine? It calls attention to the brain-like activity of the regular nucleus in cells that don't have a macronucleus, and of the raw DNA in a bacterium.

ada1981 6y ago

And 4 years ago they even won the electoral college!

arnoooooo 6y ago

This reminds me of Donald Hoffman's theory of conscious agents. He posits the simplest conscious agent to be a binary one : it can make only one kind of decision, with only two possibilities.

OnACoffeeBreak 6y ago
Here is a discussion between Donald Hoffman, Sam Harris and Annaka Harris about Hoffman's ideas on consciousness: https://samharris.org/podcasts/178-reality-illusion/ https://samharris.org/podcasts/178-reality-illusion/

im3w1l 6y ago

Ok so cells make decisions. But what about organelles with independent dna - what about mitochondria and plastids?

Retric 6y ago
Yes, though the details vary quite a bit. https://en.wikipedia.org/wiki/Regulation_of_gene_expression https://en.wikipedia.org/wiki/Regulation_of_gene_expression

dr_dshiv 6y ago

So an individual person is extremely complex -- so a simple storefront business could easily be simpler than a person. Similarly, a single cell is incredibly complex -- so a simple multicellular organism (like a worm) could easily be simpler than a cell. We all began as single cells (zygotes) and somewhere along the way we suddenly became conscious, whereas a moment before, we were not conscious. What was that point in time?

gameshot911 6y ago
>We all began as single cells (zygotes) and somewhere along the way we suddenly became conscious, whereas a moment before, we were not conscious. You may not have realized it, but many would debate the assumptions in that sentence. ^_^ Sidestepping a decent into the definition of 'conscious' itself for now, one could propose that consciousness is an inherent nature of matter itself, and it just emerges further/grows in complexity as the zygote develops.
- visarga 6y ago
  A more justified explanation would be that consciousness is the capacity to learn and adapt to the environment, so we don't have to say 'it just emerges'. It's there, even at cell level, but it's not inherent in matter, that makes no sense. It's probably inherent in self replicators that live in a competitive environment, but not just any matter. Rocks don't learn and adapt and have no reason to do so.
- mensetmanusman 6y ago
  Is there evidence of humans that skip the zygote phase of life?
  - dr_dshiv 6y ago
    lol, no -- but one could imagine splitting up stem cells to grow new humans
- ncmncm 6y ago
  Since "conscious" is an aggressively undefined term, you can say anything about it that feels good. I say "aggressively" because any attempt at a precise operational definition brings random testy objections out of the woodwork, typically invoking varying degrees of woo. Ultimately, nobody has determined a practical need for a definition, or really for the word, outside of discussion of people in comas, so reasonable people let it go.

robotresearcher 6y ago

'Makes decisions' is a terrible headline for this story. A thermostat makes decisions. 'Makes a suprisingly sophisticated series of decisions' is more supportable. But whether you are surprised depends on your intuition about how complex a tiny machine with feedback from sensors and quite a lot of internal state can be. Since almost every biological system I've ever learned anything about is mind-bogglingly rich with complex dynamics, my default is to be unsurprised by rich externally-observable behavior.

eli_gottlieb 6y ago
> 'Makes decisions' is a terrible headline for this story. A thermostat makes decisions. Well yes, that's the point. They found that prospective control goes faaaaaaaaaar back in evolutionary history.

typedef_struct 6y ago

Serious question: if I reframe the carnot heat engine as a decision making process that heat undergoes, can I publish a biology paper on it?

TaupeRanger 6y ago

It's all about oscillatory patterns. These occur in all living things, it's just that brains are especially good at creating and maintaining them.

musicale 6y ago

Appropriate for the election.

sodii 6y ago

Biochemical signal transduction networks, consisting of receptors and enzymes, are very similar to artificial neural networks, in terms of computational structure.

zalkota 6y ago

I enjoy the theory that microtubules contain mini quantum computers that derive consciousness.

FerretFred 6y ago

Great! Maybe we (Britain) can appoint it as Prime Minister in the next election. Gotta be better than what we have now.

ncmncm 6y ago

This seems an appropriate topic in connection with the recent posting[0] about Charles Turner. I hope his work appears in the reference list, alongside the Harvard eugenicist. I know which neglected body of work I think is the more significant. [0] https://news.ycombinator.com/item?id=24949335 https://news.ycombinator.com/item?id=24949335

juancn 6y ago

I don’t get what’s surprising. DNA transcription is computation. Decision making only needs the most basic of conditional information processing. Pretty much any regulatory process leading to homeostasis is a form of decision making.