4 ms·

Once an instruction has an edge, even if only extremely slight, that’s enough to tip the scales and rally everyone to that side. And this, interestingly, is wh

by defrost 7mo ago

Once an instruction has an edge, even if only extremely slight, that’s enough to tip the scales and rally everyone to that side. And this, interestingly, is why life on earth uses left-handed amino acids and right-handed sugars .. and why left handed sugar is perfect for diet sodas.

praptak 7mo ago
You still need to explain why this case creates a positive feedback loop rather than a negative one. I mean left/right fuel intakes in cars and male/female ratios somehow tend to balance at 50/50.
- defrost 7mo ago
  Wrt amino acids and sugars I personally don't have to explain as a good many others have already. eg: For one, Isaac Asimov in the 1970s wrote at length on this in his role as a non fiction science writer with a Chemistry Phd > male/female ratios somehow tend to balance at 50/50. This is different to the case of actual right handed dominance in humans and to L- Vs R- dominance in chirality ... ( Men and women aren't actual mirror images of each other ... )
- phenol 7mo ago
  products of an asymmetric reaction performed without enantiomeric control can selectively catalyse the formation of more products with the same handedness -- this is called autocatalysis. so the first full reaction might produce a left-handed product (by chance) but that left-handed product will then cause future products to be preferentially left-handed. see the [Soai reaction](https://en.wikipedia.org/wiki/Soai_reaction?wprov=sfla1 https://en.wikipedia.org/wiki/Soai_reaction?wprov=sfla1) for an example of this. as mentioned by others this is conjectural but it is a popular (if somewhat unfalsifiable) explanation for homochirality
- ben_w 7mo ago
  Regarding gender ratios: https://en.wikipedia.org/wiki/Fisher's_principle https://en.wikipedia.org/wiki/Fisher's_principle There's exceptions, but they tend to be colonial animals in the broadest sense e.g. how clownfish males are famously able to become female but each group has one breeding male and one breeding female at any given time*, or bees where the males (drones) are functionally flying sperm and there's only one fertile female in any given colony; or some reptiles which have a temperature-dependent sex determination that may have been 50/50 before we started causing rapid climate change but in many cases isn't now: https://en.wikipedia.org/wiki/Temperature-dependent_sex_determination https://en.wikipedia.org/wiki/Temperature-dependent_sex_dete... * Wolves, despite being where nomenclature of "alpha" comes from, are not this. The researcher who coined the term realised they made a mistake and what he thought of as the "alpha" pair were simply the parents of the others in that specific situation: https://davemech.org/wolf-news-and-information/ https://davemech.org/wolf-news-and-information/
  - bonzini 7mo ago
    Temperature-dependent sex determination may not be at equilibrium now but is not an exception to Fisher's principle. The temperature at which sex determination switches is variable based on the parent's genes, and it will try to re-equilibrate with the environment temperature to obtain 1:1 ratios just like in other animals.
    - ben_w 7mo ago
      Indeed, that is why I wrote "may have been 50/50 before we started causing rapid climate change".
      - bonzini 7mo ago
        It's still not a violation of Fisher's principle, long term we would see natural selection move the threshold temperature upwards.
- tbrownaw 7mo ago
  > left/right fuel intakes in cars Are I believe chosen by intelligent humans who are deliberately trying to keep the lines at gas stations balanced.
- NetMageSCW 7mo ago
  As someone with a right side fuel intake, that’s certainly isn’t true in the US. Left side fuel intake dominates completely and when the 8 pump station I prefer is busy, I only ever see left hand intake cars being fueled from the “wrong” side.
JuniperMesos 7mo ago
This is a hypothesis about why the chirality of life on earth is what it is, but I don't think there's enough evidence to state that this (or any competing hypothesis) is definitely the correct explanation.
- defrost 7mo ago
  Well "definitely correct" has no real place in probabilistic arguments almost by ipso factum absurdum :-) The chirality argument made is more akin to dynamic systems balance; yes, you can balance a pencil on its point .. but given a bit of random tilt one way or the other it's going to tend to keep going and end near flat on the table.
saati 7mo ago
> and why left handed sugar is perfect for diet sodas If you want to get diarrhea.

by defrost 7mo ago

praptak 7mo ago

You still need to explain why this case creates a positive feedback loop rather than a negative one. I mean left/right fuel intakes in cars and male/female ratios somehow tend to balance at 50/50.

defrost 7mo ago
Wrt amino acids and sugars I personally don't have to explain as a good many others have already. eg: For one, Isaac Asimov in the 1970s wrote at length on this in his role as a non fiction science writer with a Chemistry Phd > male/female ratios somehow tend to balance at 50/50. This is different to the case of actual right handed dominance in humans and to L- Vs R- dominance in chirality ... ( Men and women aren't actual mirror images of each other ... )
phenol 7mo ago
products of an asymmetric reaction performed without enantiomeric control can selectively catalyse the formation of more products with the same handedness -- this is called autocatalysis. so the first full reaction might produce a left-handed product (by chance) but that left-handed product will then cause future products to be preferentially left-handed. see the [Soai reaction](https://en.wikipedia.org/wiki/Soai_reaction?wprov=sfla1 https://en.wikipedia.org/wiki/Soai_reaction?wprov=sfla1) for an example of this. as mentioned by others this is conjectural but it is a popular (if somewhat unfalsifiable) explanation for homochirality
ben_w 7mo ago
Regarding gender ratios: https://en.wikipedia.org/wiki/Fisher's_principle https://en.wikipedia.org/wiki/Fisher's_principle There's exceptions, but they tend to be colonial animals in the broadest sense e.g. how clownfish males are famously able to become female but each group has one breeding male and one breeding female at any given time*, or bees where the males (drones) are functionally flying sperm and there's only one fertile female in any given colony; or some reptiles which have a temperature-dependent sex determination that may have been 50/50 before we started causing rapid climate change but in many cases isn't now: https://en.wikipedia.org/wiki/Temperature-dependent_sex_determination https://en.wikipedia.org/wiki/Temperature-dependent_sex_dete... * Wolves, despite being where nomenclature of "alpha" comes from, are not this. The researcher who coined the term realised they made a mistake and what he thought of as the "alpha" pair were simply the parents of the others in that specific situation: https://davemech.org/wolf-news-and-information/ https://davemech.org/wolf-news-and-information/
- bonzini 7mo ago
  Temperature-dependent sex determination may not be at equilibrium now but is not an exception to Fisher's principle. The temperature at which sex determination switches is variable based on the parent's genes, and it will try to re-equilibrate with the environment temperature to obtain 1:1 ratios just like in other animals.
  - ben_w 7mo ago
    Indeed, that is why I wrote "may have been 50/50 before we started causing rapid climate change".
    - bonzini 7mo ago
      It's still not a violation of Fisher's principle, long term we would see natural selection move the threshold temperature upwards.
tbrownaw 7mo ago
> left/right fuel intakes in cars Are I believe chosen by intelligent humans who are deliberately trying to keep the lines at gas stations balanced.
NetMageSCW 7mo ago
As someone with a right side fuel intake, that’s certainly isn’t true in the US. Left side fuel intake dominates completely and when the 8 pump station I prefer is busy, I only ever see left hand intake cars being fueled from the “wrong” side.

JuniperMesos 7mo ago

This is a hypothesis about why the chirality of life on earth is what it is, but I don't think there's enough evidence to state that this (or any competing hypothesis) is definitely the correct explanation.

defrost 7mo ago
Well "definitely correct" has no real place in probabilistic arguments almost by ipso factum absurdum :-) The chirality argument made is more akin to dynamic systems balance; yes, you can balance a pencil on its point .. but given a bit of random tilt one way or the other it's going to tend to keep going and end near flat on the table.

saati 7mo ago

> and why left handed sugar is perfect for diet sodas If you want to get diarrhea.