Nature in Code Simulations

Genetic Drift

This graph shows the frequency of a neutral allele (p) over time, based on a "one locus, two alleles" model.

Migration

When individuals mate with genetically similar individuals, inbreeding is the consequence. In this stochastic, individual-based spatial simulation, individuals can only mate with their immediate local neighbors. This results in a reduction in heterozygosity, measured by the inbreeding coefficent F (the fractional difference of observed heterozygotes from that expected from universal mating).

Epidemics

This is a spatial simulation of an epidemic using the SIR (susceptible, infected, recovered) model. It also implements the small world property by which a small fraction of contacts between infected and susceptible individuals occurs at random.