This code is a Python implementation of this video using the Pyglet library. The main idea is that a bunge of entities (arrows) have to eat green targets (food) and avoid red targets (poison).
Each entitie has a dna that contains four qualities:
Food attraction
Posion attraction
Food perception
Poison perception
Food and poison attraction can be negative or positive, and the dna is initialized randomly for each arrow.
The life of each entity decreases some quantity each frame. If the entity hits a green target its life is slightly increased and if it hits a red target it is slightly deacresed. When its life decreases to zero, the entitie desappears. When all entities of a generation desapear, a new generation is created, inheriting the dna of the previous one. Each time the inheritence takes place, there is a tiny possibility that some quality of the dna got slightly modified.
Not only this: an entitie can build a clone with its same dna. This probability is also very small, and so just the entities that live long enough could clone themselves and pass its dna to the clone. At the end of the day, just the entities with the best dna will survive and pass its genes to the next generation.