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The first 2 billion years was single celled. Since then, life on earth has been a combination of single celled prokaryotic cells, and much larger (100x) eukary
by wombatmobile 6y ago
The first 2 billion years was single celled. Since then, life on earth has been a combination of single celled prokaryotic cells, and much larger (100x) eukaryotic cells.
The evolution of eukaryotes, which comprise all the plants and animals you see on David Attenborough's Life on Earth show, didn't occur until the Earth had developed an oxygen rich atmosphere.
What's amazing about eukaryotic cells is that they formed from colonies of prokaryotic cells, in a process called endosymbiosis.
There's a reason why the mitochondria in eukaryotic cells look like little bacteria like organisms. They actually were once separate prokaryotic organisms. Same for chloroplasts in plant cells.
How Two Microbes Changed History
https://www.youtube.com/watch?v=lhF5G2k45vY&t=343s https://www.youtube.com/watch?v=lhF5G2k45vY&t=343s
- jfarlow 6y agoSearch space for the first billion or so years was likely around atoms/chemistry. Search space for the next billion or so years was likely around mutations in well-defined genetic space (4 nucleic acids as building blocks, 20 amino acids as building blocks). Search space for the past 700M years has included 'recombination' (copy/swap/paste) of larger chunks of (existing) genetic code (in addition to the prior two mechanics). There are probably many such abstraction layers, including like you mention, copying/pasting of entire organisms, environments, biospheres...