There seems to be some kind of memory leak in the game which causes it to crash after running for a while(usually about 750 generations at 10 seconds per generation, 40 specimens)

I have this exact problem and the only solution I have is to save the simulation before it gets too laggy and then exit the game then replay it. If you're planning to have it run overnight, turn autosave on. But yeah, it is quite annoying and should probably be fixed, if it can.

yeah, i've got some pretty good runners but it always crashes after a hundred or so generations. it's best if you turn on autosave

There will be a lot of significant memory usage optimizations in the next update, so I'm hoping that that's going to fix it.