You'd have to add more detail to answer the first question. The paper color represents some trait of the beetles, maybe color. If some colors had more squares at the end then whatever that trait was, it was favored (either fewer of them died, or they had more babies). Picking up squares is death (maybe from predation) Adding squares is births (having babies) This is what natural selection is. Some traits are favored such that the beetles that have them are less likely to die and more likely to have babies. So, every generation, there are more of those types of beetles added to the population. Hope this helps.