Home Range

This simulation was developed as a part of a project in one of my courses. It uses the same Evolutionary Algorithm Framework as in our Natural Selection among random walks simulation. Animals (triangles) have a single behavioural gene with two nucleotides. One controls their homesickenss instinct whereas the other controls their exploration instinct. Every animal's behaviour is influenced by these two instincts.

Food distribution across the world is modeled in form of a grid. A cell with food is light grey whereas one without food is black. When an unsaturated animal walks into a cell with food, it consumes it. After certain time of starvation, an animal dies. Food is generated according to the regeneration rate specified by the user.

Additionally, the world consists of predators (red circles). They move randomly. In general, they avoid the home range of the animal but the boundary is not sharp. If a predator gets very close to an animal, it kills the animal. No hunger or behavioural dynamics are present in the predator (for sake of simplicity). Number of predators can be controlled by the user.

Every time an animal dies due to starvation or predation, another animal is generated. It obtains it's genes from it's parents, subjected to the processes of recombination and mutation. The parents are chosen from the alive animals, based on their fitness. Fitness is calculated on the basis of lifespan.

Indicators: The blue circle represents the distance from the home (origin) at which homesickness instinct becomes half maximum. A saturated animal is blue in colour. The more starved an animal is, the redder it becomes. A death is signaled by an expanding circle. At the top of the canvas, the blue section indicates prevalence of the homesickness instinct whereas the red section indicates that of the exploration instinct.


Number of Animals


Analysis

Factors that induce homesickness: High rate of food regeneration, low population of animals and high number of predators. Generally speaking, homesickness instinct is prevalent in most cases. This shows that it is an extremely important instinct to possess for the sake of survival.

Factors that induce exploration: Low rate of food regeneration, high population of animals and low number of predators.


Note:
  1. Since every death is replaced, the population stays constant. If you want to simulate with a different population size, enter the intended population size in the input and click on the restart button.
  2. Rate of predation and rate of food regeneration can be adjusted dynamically. It takes considerable time for allele frequencies to change after such changes are made
  3. Refer to this document for more details on modelling
  4. Compared to the predators, the animals are actually smarter. Animals can sense food from a certain radius (dependent on their exploration instinct). Once they find food, they steer towards it.
  5. The food sensing instinct is a bit buggy. If an animal finds food in multiple equidistant locations, it may spend some time incessantly turning in the same location, before choosing one location to pursue.


Developed by ChanRT | Fork me at GitHub