The genebank

• At the start of the simulation, 15 species are downloaded from the genebank and populated into the world in a random location. These species are chosen at random from the species who have gone extinct the least number of times. These should be the most competitive species. In practice, there are so many new species evolving that once a species goes extinct once, their chances of being revived are slim.
• If a new species evolves and shows that it is valid and competitive, it is saved to the genebank. 'Valid and competitive' means that there must be at least 10 alive.
• A species can show that it is successful by having at least 75 animals alive at one time. The species receives a "+1" in the genebank.
• If a species goes extinct, then the genebank is also notified. The species receives a "-1" in the genebank.
• A species is defined by the genome (memory) of the animal at birth. Animals of the same species have exactly the same genome.
• The simulation can be paused or resumed at any time with no ill effects to the genebank.

Living and dying

• Each period, every process gets the chance to execute.
• If a process has multiple threads, each thread will be executed.
• A thread may be set to run at a higher clock speed, this allows the thread to execute arbitrarily many instructions in a single period.
• The cost of executing each instruction is speed², for a thread running at the default speed, this is 1.
• At the end of each period, all live animals are given 1 cputime credit.
• A thread may sleep for an arbitrarily long time. During this time the thread incurs no execution cost, and the animal continues to earn cputime credit.
• If an animal ever runs out of cputime, it dies.

Attack and defend

• Animals can attack each other by attempting to move onto the others space (kind of like chess).
• Both the attacker and the defender lose cputime from the battle. The defender loses min(attacker.cpu,defender.cpu), and the attacker loses 90% of this same amount, (the benefit of surprise?)
• If the defender's cputime drops to zero, then the defender dies, and the attacker gets the value of the remains in cputime.
• The attacker can never die in battle, but can become quite low on cputime.
• The value of the remains is calculated as 5 * defender.memory.length.

Reproduction

• To reproduce itself, an animal allocates memory, writes the new child to the allocated memory, and then divides from the child. Current animals all copy themselves, but there is potential to write different information to the child (perhaps a compressed version and a decompressor?)
• This writing process is intentionally flawed, and each write has a 1/1000 chance of containing an error. This induces mutations, and allows the opportunity for evolution.
• The child will be placed in front of the parent (in the direction that the parent is facing) and will face the same direction.