This is the minimal organism sim I have running where I started out with a pretty minimal 14bp single gene bot that only shoots (endlessly) and reproduces. The only cost in the system is a small nrg/cycle cost to keep the population down. After 600k cycles, the average DNAlen has grown to 17 and the average # of mutations is over 9.
But here's a funny thing. All my bots are oriented the same way, firing a stream of shots pretty much horizontal either left or right. I wonderred what would casue that?
It took me while to figure it out, but I think its selection for orientation. Take a look at the attached jpg and you can see my incubator habitat for my bots. Because they can't turn or move on their own (yet) I set up a ring of stable, high energy veggies to keep them in the nursury. Some escape and die of starvation but enough remain that I'm 750+ generations down the road.
Now, clearly, if you arn't lined up like all the other guys in the nursury, you are at a disadvantage. You tend to float into an endless stream of shots coming from the rest of the pack and you die pretty quick. If you are lined up right, when you give birth, your offspring has the opposite orientation. You each take a few shots until you spearate, but if you seperate fast enough, you have successfully repreoduced a bot with a survivable orienation. Viola! A heritable trait that isn't encoded in the DNA!!!. The physics of the sim don't seem to impart much rotational momentum to the bots, so bots tend to keep their orientation for quite a while, even outside the hive as you can see.
Pretty damn cool.
-E
Well, hell it won't let me attach the image. Guess we only get 100k total in all forums for attachments and I've used mine up. Too bad.