a set of individualized creatures
a Territory
a collective memory
a creature generator
A Population maintain a collective memory seems to model the exchanges of informations between individuals. This memory contains informations shared among the individuals, including the reputation of external Creatures and rumours.
Creatures of a Population (as most creatures anyway) do not spontaneously reappear (repop), they reproduce themselves. Evolutions of a Population can be consequences of:
Growth
Natural development (with sufficient resources)
Weather effect
Populations fusion
External effect (breeding, magical effect)
Diminution
Death of individuals (predators, natural disasters, etc)
Weather effect
Pollution, unadapted environment
Competition with other Populations
Insufficient resources, territory too small
Population split
Unadaptation to the flora, the fauna, or something else.
A Population can split up when the resources necessary to its survival are not available any more (too many individuals, too few resources) and the territory cannot be enlarged any more. In this case, only one of the resulting Populations stay on the Territory. In the other case (no division), the Population diminishes by lack of resources.
A nomad Population explores until it finds a convenient territory (with resources sufficient for the all or part of the Population). In the mean-time, the Population has still needs and use the resources of the territories it traverses.
An individual which leaves the Population is not affected by advantages and constraints linked to this Population (collective memory, mutual protection,etc). When it meets another Population of the same kind, it can ask for admission and be accepted or not (an attack from the Population is even possible). When it meets another individual of the same kind (and sexually compatible), they can settle a new Population.
To simulate natural growth, a new Creature is generated after a delay computed by a random variable (dependent of the Population) and only when some conditions are met (example: existence of a reproducer couple). This new Creature is created according to a template which evolves with the recent experience of the Population. A pacifist Population, if it is regularly under attack, will produce more young warriors. (If not, the Population will more likely flee out of this Place).
Creatures of new generation have characteristics transmitted by precedent generations (inheritance concept).
When there is no more individual in a Population, this one is declared extinct. the section called Species Protection>