How far does the process go?

[IcewaterCreek®]

So ecosystem in balance... reached all plants unlocked in the first area!
So now I ponder... if one would let the game run, let's say... while sleeping... fish evolution will go as far as ________?

 

[Serafine]

I've let the game run for several hours and my fish get constantly better at fast swimming and turning. Some people had fish evolving super-complicated massive neural networks which completely tanked performance (there's a fix for that now i believe) but mine did none of that - in fact my performance somehow increased over time as fish got more efficient at swimming (and there were less fish that tried to break the game engine physics).
Also i haven't tested this with the newest version yet and I guess things have changed a lot with those long runs as minor changes add up over time.