The earliest signs of life at >3.5B years old [1] while photosynthesis dates to ~3.4B years ago. That seems to be pretty quick (by some definition, ~100 million

The earliest signs of life at >3.5B years old [1] while photosynthesis dates to ~3.4B years ago. That seems to be pretty quick (by some definition, ~100 million years with huge error bars is "quick"). If photosynthesis only evolved once, another explanation is that it only needed to once because it was so wildly successful. Multicellular is interesting. That obviously took much longer but once it did? Holy crap did things take off. I kinda wish I could have a time machine just to visit the Cambrian Explosion era. [1]: https://en.wikipedia.org/wiki/Evolution_of_photosynthesis https://en.wikipedia.org/wiki/Evolution_of_photosynthesis