Overview of HexSim Populations


The Properties Tab

The properties tab controls the initial population size and placement, whether an exclusion series is to be used, and whether genetics are implemented in the scenario.

The Range Tab

The range data are used in HexSim to control group and range formation. Groups are collections of individuals, such as packs, herds, flocks, etc. Ranges can be used to simulate defended territories, since they are non-overlapping. Home ranges might be approximated by explored areas, since these can extend beyond a range, and can overlap. The Adjust Range Parameters event can be used to alter these parameters. These values are used primarily by the exploration component of Movement events, and by Range Dynamics events, since these events principally control group and range construction, and maintenance.

The Traits Tab

The traits tab is where user will define individuals' traits. Every population must have at least one trait. HexSim's traits can be probabilistic, accumulated (changing with time or exposure, etc.), or genetic. Traits are really just collections of mutually exclusive trait values. Individuals can only have a single trait value at a time, for any single trait. Part of a trait's definition is a set of rules governing the assignment of trait values. For example, a stage-class trait might be composed of three trait values: juvenile, subadult, and adult.

The Affinities Tab

Affinities are defined in the Population Data's Affinities tab. HexSim has five kinds of affinities: Natal, Reproduction, Resource, Group Movement, Spatial. Affinities are stored by Reproduction, Exploration, Set Group Affinity, and Set Spatial Affinity events. Affinities are used by the dispersal component of Movement events. When affinities are supplied to dispersal, they control an individual's choice of direction through the autocorrelation mechanism. The result is that individuals tend to move towards the affinity site.

HexSim Genetics

Genetics in HexSim consists of several interacting components. A genome is created for each population. Genotypes are assigned to the individuals that make up the starting population. Rules are established for inheritance. Mutation events may be developed and used to alter individual genotypes. And genetic traits can be developed that derive observable characteristics from individual genotypes.

Resource Allocation

Each individual has a location, and regions of space that it can access. These regions are referred to as explored and allocated areas. Explored areas are collections of hexagons that an individual has visited. Allocated areas are collections of hexagons that an individual has more exclusive access to and from which they are able to extract resources.