4 ms·

I read a paper a long while back that used purely numerical arguments to first show a common rate in the growth of complexity across biological and non-biologic

I read a paper a long while back that used purely numerical arguments to first show a common rate in the growth of complexity across biological and non-biological systems under similar conditions. It then plotted this exponential growth backwards in time, showing that life's origins were prior to the formation of earth by about 1.5 billion years. No guesswork, it was quite solid; the same math applied to human technology traces back to roughly its known start on earth. It was convincing that life is prolific in the universe but intellgent life took about 6-9 billion years to go from single cell to us.

jiggawatts 11mo ago
Obligatory: https://xkcd.com/605/ https://xkcd.com/605/ That paper used a horribly faulty logical argument because it has been well known for quite a while that most of the time evolution is quite slow, but there are short bursts of rapid change. For example: https://en.wikipedia.org/wiki/Cambrian_explosion https://en.wikipedia.org/wiki/Cambrian_explosion See: https://en.wikipedia.org/wiki/Punctuated_equilibrium https://en.wikipedia.org/wiki/Punctuated_equilibrium
- d4rkn0d3z 11mo ago
  The "obligatory" doesn't apply since that paper did not extrapolate. It would be the exact opposite. I'm pretty sure the issue you raise is averaged away quite neatly by the math.
  - jiggawatts 11mo ago
    They literally extrapolated backwards in time. Extending your data in time is extrapolation, whether that’s forward or backward!
    - deleted 11mo ago
      [deleted]
    - d4rkn0d3z 11mo ago
      How do you think we determine the age of the universe? The age of rocks? Do you not accept carbon dating? You could call this technique "complexity dating". First you show there is exponential growth (or decay) occuring naturally. The actual changes occur randomly but the mean rate is fixed. Then you plot on log scale and voila you have complexity dated life itself. The only argument you can make against is that the laws of physics are somehow not constant, but I think everything froze out by the time molecules were forming. So in your cartoon, the bride can marry a random normally distributed number of husbands each time. We would determine the average rate of husband accretion. Then given the number of husbands at any time we could determine when the rapacious bride began marrying.
      - jiggawatts 11mo ago
        > How do you think we determine the age of the universe? Inaccurately, with recent revisions to the tune of hundreds of millions of years. > The age of rocks? Surprisingly inaccurately, despite the smooooooooth exponential curve of radioactive decay. Evolution is not smooth. > Do you not accept carbon dating? I do, within its error range. Which is large. Like tens of percent in common scenarios.
        d4rkn0d3z 11mo ago
        Indeed the error range here is about 1.5 to 2 billion years. So from the paper we know that life began its growth in complexity about 6-9 billion years ago. This is strictly from numerical arguments. Evolution is just a random choice in the number of husbands per ceremony.
        jiggawatts 11mo ago
        There are two fundamental issues with evolutionary "clock" models getting extrapolated too far backwards: 1. The rate of change-per-generation is very much not constant, as described by the Punctuated Equilibria theory. Sudden changes in the environment can cause sudden bursts of evolution. We don't know if there were any (and how many) mass extinctions / sudden change events before the fossil record starts, which is already hundreds of millions of years into the existence of single-celled life existing! 2. The time elapsed per generation has changed over time too, and we have virtually no direct evidence of the actual rate for the earliest epochs of life, before multi-cellular life. These are particularly bad problems for any theory trying to extrapolate backwards, with compounding issues that can blow out any naive error estimates massively. For example: RNA-based vs DNA-based life. We know that DNA is more stable and resistant to mutation than RNA, which was the foundation of the earliest life forms. But we have no idea how that difference specifically affected early life evolutionary rates! We can guess... but only guess. However, almost certainly, early life had a much higher mutation rate per generation than modern life AND a consistently short generation time.

jiggawatts 11mo ago

Obligatory: https://xkcd.com/605/ https://xkcd.com/605/ That paper used a horribly faulty logical argument because it has been well known for quite a while that most of the time evolution is quite slow, but there are short bursts of rapid change. For example: https://en.wikipedia.org/wiki/Cambrian_explosion https://en.wikipedia.org/wiki/Cambrian_explosion See: https://en.wikipedia.org/wiki/Punctuated_equilibrium https://en.wikipedia.org/wiki/Punctuated_equilibrium

d4rkn0d3z 11mo ago
The "obligatory" doesn't apply since that paper did not extrapolate. It would be the exact opposite. I'm pretty sure the issue you raise is averaged away quite neatly by the math.
- jiggawatts 11mo ago
  They literally extrapolated backwards in time. Extending your data in time is extrapolation, whether that’s forward or backward!
  - deleted 11mo ago
    [deleted]
  - d4rkn0d3z 11mo ago
    How do you think we determine the age of the universe? The age of rocks? Do you not accept carbon dating? You could call this technique "complexity dating". First you show there is exponential growth (or decay) occuring naturally. The actual changes occur randomly but the mean rate is fixed. Then you plot on log scale and voila you have complexity dated life itself. The only argument you can make against is that the laws of physics are somehow not constant, but I think everything froze out by the time molecules were forming. So in your cartoon, the bride can marry a random normally distributed number of husbands each time. We would determine the average rate of husband accretion. Then given the number of husbands at any time we could determine when the rapacious bride began marrying.
    - jiggawatts 11mo ago
      > How do you think we determine the age of the universe? Inaccurately, with recent revisions to the tune of hundreds of millions of years. > The age of rocks? Surprisingly inaccurately, despite the smooooooooth exponential curve of radioactive decay. Evolution is not smooth. > Do you not accept carbon dating? I do, within its error range. Which is large. Like tens of percent in common scenarios.
      - d4rkn0d3z 11mo ago
        Indeed the error range here is about 1.5 to 2 billion years. So from the paper we know that life began its growth in complexity about 6-9 billion years ago. This is strictly from numerical arguments. Evolution is just a random choice in the number of husbands per ceremony.
        jiggawatts 11mo ago
        There are two fundamental issues with evolutionary "clock" models getting extrapolated too far backwards: 1. The rate of change-per-generation is very much not constant, as described by the Punctuated Equilibria theory. Sudden changes in the environment can cause sudden bursts of evolution. We don't know if there were any (and how many) mass extinctions / sudden change events before the fossil record starts, which is already hundreds of millions of years into the existence of single-celled life existing! 2. The time elapsed per generation has changed over time too, and we have virtually no direct evidence of the actual rate for the earliest epochs of life, before multi-cellular life. These are particularly bad problems for any theory trying to extrapolate backwards, with compounding issues that can blow out any naive error estimates massively. For example: RNA-based vs DNA-based life. We know that DNA is more stable and resistant to mutation than RNA, which was the foundation of the earliest life forms. But we have no idea how that difference specifically affected early life evolutionary rates! We can guess... but only guess. However, almost certainly, early life had a much higher mutation rate per generation than modern life AND a consistently short generation time.