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I don't have anything particularly insightful to share except that it has occurred to me and that thinking about it seems like a deep rabbit hole. It's probably
by netcan 13y ago
I don't have anything particularly insightful to share except that it has occurred to me and that thinking about it seems like a deep rabbit hole. It's probably a key to figuring out how it all got started in the first place.
DNA does seem too complex to have sprung into being fully formed. Also, DNA & RNA probably share a lineage which suggests they the are evolved.
The basic rules of the evolution game in the plant and animal kingdoms seem to be genes encoded in DNA passed through sexual reproduction. These are the mechanisms we think of when we think of evolution. Darwin didn't know about genes or DNA so he used "organisms" as the basic unit and that seems to work just as well. This is a pretty stable long term system. It seems to be the main way organisms evolve.
But, these aren't the only rules/mechanisms of biological evolution. For a start, it doesn't explain how these rules got written. We know that there are other mechanisms for inheritance of genetic traits, "epigenetic" seems to be the general word for them. Richard Dawkins describes "memes" as units of culture which evolve in societies. Humans are organisms.
The rules and mechanisms that govern evolution are certainly subject to change and there are various mechanisms, perhaps competing. For example, right now there is a transmittable cancer tearing through the Tasmanian Devil population. The cancerous cells are transmitted when devils bite each other. The cancer itself can be considered an organism, like a virus or a bacteria. It has cells and reproduction and genes. It behaves similarly to a bacteria or virus but it's a descendant of a tasmanian devil (or a devil's cell).
So we have an example of an leap (or fall). The basic rules got broken in a way that. The evolutionary unit (tasmanian devil) was ignored in favor of a new unit (cell). Most the rules that apply to the previous unit (eg sexual reproduction) no longer apply. It's a reminder that the genes themselves that are "trying" to reproduce. The cell is a vehicle for the gene. The organism is a vehicle for the cell.
Did "Devil Facial Tumour Disease" evolve? I'm not sure we can call it evolution. But, it wasn't the first cancer that had a chance to become its own organism. Every cancerous mutation is an opportunity for a transmittable cancer to pop into existence. Given enough time, maybe it evolve into Maybe it will develop organs and limbs and fur and then maybe it will develop its own parasitic cancer: generation 2.
Sexual reproduction is itself a mutation that probably occurred several times and it changes the rules. Epigenetics seems to be in the zetgeist at the moment, I hear the term mentioned a lot.
I don't know how to tie these thoughts together.
Douglas Adams is my go to for these kinds of issues:
“Anything that happens, happens. Anything that, in happening, causes something else to happen, causes something else to happen. Anything that, in happening, causes itself to happen again, happens again. It doesn’t necessarily do it in chronological order, though.”
Like I started earlier on, I my instinct is that evolution the principle is best explored outside of biology. Biology is a magnificent example of evolution, but it's an embodiment of evolution.
"Anything that, in happening, causes itself to happen again, happens again" seems like a good starting point.
- jacquesm 13y agoThank you! Makes you wonder what the minimum viable product version of DNA supporting 'life as we recognize it' was like... Maybe CG or TA only?