• A single-celled organism capable of learning
    16 replies, posted
[I]via: [/I][I]ScienceDaily [/I][quote]For the first time, scientists have demonstrated that an organism devoid of a nervous system is capable of learning. A team from the Centre de Recherches sur la Cognition Animale (CNRS/Université Toulouse III -- Paul Sabatier) has succeeded in showing that a single-celled organism, the protist [I]Physarum polycephalum[/I], is capable of a type of learning called habituation. This discovery throws light on the origins of learning ability during evolution, even before the appearance of a nervous system and brain. It may also raise questions as to the learning capacities of other extremely simple organisms such as viruses and bacteria. These findings are published in the [I]Proceedings of the Royal Society B[/I] on 27 April 2016.[/quote] [URL="https://www.sciencedaily.com/releases/2016/04/160427081533.htm"]Source [/URL] [url]http://dx.doi.org/10.1098/rspb.2016.0446[/url]
[QUOTE=ExplodingGuy;50212303][/QUOTE] It begins our downfall.
I don't quite understand from reading the abstract, is it implying that using the quinine and caffeine will exhibit a response only if they're introduced in a staggered rate? How can that show that is 'learning', what if its just a biological response as a result of how the organism is comprised? How is that any different from say developing a tolerance?
[QUOTE=Lone Wolf807;50212687]I don't quite understand from reading the abstract, is it implying that using the quinine and caffeine will exhibit a response only if they're introduced in a staggered rate? How can that show that is 'learning', what if its just a biological response as a result of how the organism is comprised? How is that any different from say developing a tolerance?[/QUOTE] It means that the behaviour exhibited by the organism is indistinguishable (at least, as far as they can tell) from neural habituation which is a pretty well agreed upon form of learning. The idea of 'building up a tolerance' is correct and, when you think about it, is indeed a form of learning. The organism 'learns' (whether by its biological composition or otherwise) to ignore the stimuli for a certain amount of time and then responds immediately when later introduced to it, just like neural habituation.
fuckin sweet deal, the more we learn about learning the better. learning is looking more and more like something universal to life since plants can learn as well
[QUOTE=Passing;50212405]It begins our downfall.[/QUOTE] We'll be prepared... in like 300 million years.
I wonder if this could be utilized for biological computing
[QUOTE=cody8295;50213958]I wonder if this could be utilized for biological computing[/QUOTE] We already are utilized for biological computing.
I'm wondering if this is the sort of thing pro-life proponents would use to defend their stance on the life status of embryos or fetuses. Can anyone say with confidence if the organism they tested in this experiment is similar or different from developing offspring?
[QUOTE=Bat-shit;50213763]We'll be prepared... in like 300 million years.[/QUOTE] Or dead.
[QUOTE=Drewsko;50214850]I'm wondering if this is the sort of thing pro-life proponents would use to defend their stance on the life status of embryos or fetuses. Can anyone say with confidence if the organism they tested in this experiment is similar or different from developing offspring?[/QUOTE] Whether or not the fetus is alive isn't in argument. Of course it's alive, it's a grouping of human cells which are, by definition alive. These single-celled organisms would still be alive if they didn't have this learning capacity. The actual question that's in debate is whether or not the fetus is a person and has rights. Moreover, this single-celled organism doesn't have rights anyway so it doesn't really apply at all.
[QUOTE=Mort Stroodle;50215567]Whether or not the fetus is alive isn't in argument. Of course it's alive, it's a grouping of human cells which are, by definition alive. These single-celled organisms would still be alive if they didn't have this learning capacity. The actual question that's in debate is whether or not the fetus is a person and has rights. Moreover, this single-celled organism doesn't have rights anyway so it doesn't really apply at all.[/QUOTE] Person-hood doesn't mean anything if you don't have an identity, which a fetus does not. The basis for opposition to abortion outside of a late-term context (where it is implied that there may be suffering) is strictly religious. [url]http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2797842/[/url] [url]http://plato.stanford.edu/entries/nonidentity-problem/[/url] Even basic organisms exhibit the ability to respond to stimuli, this study doesn't imply actual "learning". This is something more basic, but still is significant because the slime molds provide some insight about how the first assemblages of cells became true multi-cellular organisms.
[QUOTE=Matthew0505;50217075]Technically a single cell, but it'd be more like a bunch of neurons without cellular boundaries than a single bacteria learning.[/QUOTE] It's not at all like a bunch of neurons. Neurons are characterised by the vast network of synaptic connections they make with each other, and it's these connections (and their ability to be formed, strengthened, or broken) that allow brains to learn and adapt. This is a single cell learning and adapting purely by virtue of the chemical pathways it has within it. To give more detail, here's how the experiment worked. Each cell was made to cross an agar bridge every day to reach a food source. Three different groups of cells were used. C had to cross a plain bridge to reach the food, Q had to cross a bridge with quinine in it, and CAF had to cross a bridge with caffeine in it. The testing was done in four phases. The first phase (habituation phase) lasted for 5 days, and consisted of the aforementioned treatments. The second phase (test phase 1) lasted for a day. During this phase, half of group C was exposed to the usual treatment (which is nothing), while the other half was split between being exposed to quinine and being exposed to caffeine. Meanwhile, the Q group was split in two, with half being exposed to quinine again, and the other half being exposed to caffeine. The same thing happened with the CAF group. After that, during the third phase (recovery phase), all cells were exposed to plain agar for 2 days. During the final phase (test phase 2), the same thing was done as in test phase 1. The cells were tested for aversion based on three metrics: how long it took them to reach out for the bridge, how long it took them to cross the bridge, and how narrow or wide the pseudopod they extended across the bridge was (the bigger the pseudopod, the less the cell cares about how much it is touching the agar). What they found was this: the C cells behaved as expected. They happily crossed the bridge they were given since it had nothing foul on it, but during test phase 1, when exposed to either quinine or caffeine, they exhibited aversion to crossing the bridge. During the recovery phase, they behaved as usual, crossing the bridge rapidly. When again challenged during test phase 2, they showed aversion. The Q and CAF cells, on the other hand, showed aversion on day 1 of the habituation phase, but this aversion decreased over the course of the habituation phase. This demonstrated that they were developing some sort of tolerance to the bitter agent they were presented with. Test phase 1 is the interesting phase. Q cells, when exposed to caffeine, actually showed similar degrees of aversion as C cells, and likewise for CAF cells exposed to quinine. In other words, a cell that had become accustomed to quinine was still wary of caffeine, and vice versa. This meant that the response wasn't due to some sort of generalised tolerance to noxious stimuli, but instead a habituation response to a specific stimulus. It's a bit like someone gaining an acquired taste for hákarl, but when presented with surströmming, they still find it disgusting. Nothing remarkable to be said of the recovery phase, since it's just cells crossing plain agar. During test phase 2, however, Q and CAF cells, after 2 days of not being presented with their respective stimuli, seemed to had "forgotten" what they learnt during the habituation phase. They showed almost complete aversion to noxious stimuli (whether it was the one they had previously been exposed to or another one). The authors theorise that the cell expresses caffeine and quinine receptors on its surface, and that exposure to either stimulus results either in transient modification of the DNA (e.g. methylation, histone modification, changes in transcription factors), which changes the amount of receptors expressed on the cell surface, or in transient changes to the structure of the receptor itself, which results in a less-sensitive receptor. We don't know for sure, but at least we know where to look now for such non-neuronal learning. All in all, a pretty neat paper.
The start of the flood. Halo all over again
[QUOTE=raz r23;50218156]The start of the flood. Halo all over again[/QUOTE] Actually the flood were the Precursors whom had become enraged by their creations attack on them that had forced them to evolve into a new form of life.
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