Founder Effect & Genetic Bottleneck Simulator

Genetic diversity is the raw material a population needs to adapt — it is the range of alleles present across individuals, not just the number of genes each one carries. This simulator visualises one of the main ways that diversity gets lost: the founder effect. A small group sampled from a large, diverse mainland population (left cluster, eight alleles at one locus, coloured A–H) colonises a new island (right cluster). Because the founders are few, they can only carry a subset of the mainland's alleles, and every generation afterwards is built by randomly re-sampling the previous one — a process called genetic drift — which keeps whittling away whatever diversity survived the founding. Adjust the founder count, the island's carrying capacity and the generation speed to see how quickly alleles are lost, how heterozygosity falls, and how the inbreeding coefficient climbs when a population is squeezed through a narrow bottleneck.