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I'm amazed by how cells know what to grow 'into' as well - especially since stem cells seem to be able to grow into just about any body part? >>and thus can le

I'm amazed by how cells know what to grow 'into' as well - especially since stem cells seem to be able to grow into just about any body part? >>and thus can learn some things("instinctual behaviour") easier than others I don't understand this - Isn't 'instinctual behaviour' something you don't have to learn? Also, I wonder if there's a limit to how complex a behavior can be 'encoded'? like bright colored animals == poisonous. That requires being able to tell a say a toad from a bird, what a color is, what colors = poison, etc? That seems like a pretty complex behavior...Do we have any idea what the limit is for complex behaviors in genes? Thanks!

Llamamoe 2y ago
To be clear, I'm not an expert, but the way I imagine it is as genetically encoded biases to process information differently based on its colour, position, which neuron(s) or receptors it's coming in from, etc. that don't necessarily encode the entire neural circuitry for a behavior, but make it automatically learnable without the need for full-blown experiences, just as a consequence of the neurons developing and being exposed to normal environmental information at all.
- mech422 2y ago
  I guess I just get floored that such complex behaviors can be encoded. Like how some people seem to 'just know' how to draw and I can't draw a straight line with a ruler...
Terr_ 2y ago
> I'm amazed by how cells know what to grow 'into' as well - especially since stem cells seem to be able to grow into just about any body part? AFAIK the current explanations for this often involve electrical and chemical gradients, along with "timer" cyclic reactions among groups of cells. A contrived example: Suppose the first progenitor cell buds off two children, where one is set to be "Emit Head signals, flee from Tail signals" and the other is "Emit Tail molecules, flee from Head molecules". These two daughter-lines promptly zip off in opposite directions, and now there's a kind of chemical Head-to-Tail measure in the middle for differently-calibrated cells to arrange themselves on. Then it buds off some cells that are tuned to create a line in-between the two poles, and those cells generate/follow a certain chemical "beat" in order to subdivide, and if the beat lasts X cycles they create X striped zones, which might become chunks of a spine...
- mech422 2y ago
  Thing is, it seems to me like some sort of 'master control' needs to know what signals to emit. Which sounds like it has to have a 'blueprint' of what the entire organism should 'look' like? I always think of some lil control room going "ok..we need a heart and 2 lungs...send out the heart signals, and send out 2 lung signals" (electrical or chemical or whatever the signals are) Just amazing such 'simple' organisms manage to co-ordinate all this stuff... Thanks
  - Terr_ 2y ago
    Homeobox genes [0] are relevant when it comes to pretty high level "heads go on that end, butts go on that end" stuff. There's also this parody video of Despacito [1] that may be, er, educationally amusing. [0] https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Homeobox [1] https://www.youtube.com/watch?v=ydqReeTV_vk https://www.youtube.com/watch?v=ydqReeTV_vk
    - mech422 2y ago
      Thanks! That was pretty good...gonna see what else he has :-D ok - I have no idea what he's talking about, but both my girlfriend and I loved the ones we listened to :-D (1)(2) Thanks again! 1) https://www.youtube.com/watch?v=2rjbtsX7twc https://www.youtube.com/watch?v=2rjbtsX7twc 2) https://www.youtube.com/watch?v=f8FAJXPBdOg https://www.youtube.com/watch?v=f8FAJXPBdOg

Llamamoe 2y ago

To be clear, I'm not an expert, but the way I imagine it is as genetically encoded biases to process information differently based on its colour, position, which neuron(s) or receptors it's coming in from, etc. that don't necessarily encode the entire neural circuitry for a behavior, but make it automatically learnable without the need for full-blown experiences, just as a consequence of the neurons developing and being exposed to normal environmental information at all.

mech422 2y ago
I guess I just get floored that such complex behaviors can be encoded. Like how some people seem to 'just know' how to draw and I can't draw a straight line with a ruler...

Terr_ 2y ago

> I'm amazed by how cells know what to grow 'into' as well - especially since stem cells seem to be able to grow into just about any body part? AFAIK the current explanations for this often involve electrical and chemical gradients, along with "timer" cyclic reactions among groups of cells. A contrived example: Suppose the first progenitor cell buds off two children, where one is set to be "Emit Head signals, flee from Tail signals" and the other is "Emit Tail molecules, flee from Head molecules". These two daughter-lines promptly zip off in opposite directions, and now there's a kind of chemical Head-to-Tail measure in the middle for differently-calibrated cells to arrange themselves on. Then it buds off some cells that are tuned to create a line in-between the two poles, and those cells generate/follow a certain chemical "beat" in order to subdivide, and if the beat lasts X cycles they create X striped zones, which might become chunks of a spine...

mech422 2y ago
Thing is, it seems to me like some sort of 'master control' needs to know what signals to emit. Which sounds like it has to have a 'blueprint' of what the entire organism should 'look' like? I always think of some lil control room going "ok..we need a heart and 2 lungs...send out the heart signals, and send out 2 lung signals" (electrical or chemical or whatever the signals are) Just amazing such 'simple' organisms manage to co-ordinate all this stuff... Thanks
- Terr_ 2y ago
  Homeobox genes [0] are relevant when it comes to pretty high level "heads go on that end, butts go on that end" stuff. There's also this parody video of Despacito [1] that may be, er, educationally amusing. [0] https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Homeobox [1] https://www.youtube.com/watch?v=ydqReeTV_vk https://www.youtube.com/watch?v=ydqReeTV_vk
  - mech422 2y ago
    Thanks! That was pretty good...gonna see what else he has :-D ok - I have no idea what he's talking about, but both my girlfriend and I loved the ones we listened to :-D (1)(2) Thanks again! 1) https://www.youtube.com/watch?v=2rjbtsX7twc https://www.youtube.com/watch?v=2rjbtsX7twc 2) https://www.youtube.com/watch?v=f8FAJXPBdOg https://www.youtube.com/watch?v=f8FAJXPBdOg