As soon as the player starts generating pollution with machines like the burner miner, Time drops to 99% (Pollution remains at 0% due to rounding, presumably)
This shows that it is the *emission* of pollution that raises evolution.
However, if the player cheats in a flamethrower (for testing purposes, of course ) and sets fire to hundreds of trees, Time remains at 100% (at least until a spawner is destroyed).
Is this intended? The pollution-evolution from fire seems like it must be trivial, and I mainly ask out of curiosity after recalling the evolution factor tweaks mentioned in https://www.factorio.com/blog/post/fff-142
Forest fire doesn't seem to contribute at all though!We felt that the evolution factor growth doesn't slow down enough towards the higher value. In our specific game, it probably grew faster than usually as Scott was more than eager to test the new fire mechanics by setting every forest he found on fire. So we couldn't know what affected the evolution factor the most.