Selective Sweep & Genetic Hitchhiking Simulator (2D)

When a beneficial mutation rises to fixation under positive selection, it doesn't travel alone — every neutral variant physically linked to it on the same chromosome gets dragged along too, a phenomenon population geneticists call genetic hitchhiking. This 2D companion to the 3D Selective Sweep simulator runs the same individual-based Wright-Fisher model over a 41-site chromosome segment: each generation, offspring are sampled with probability proportional to fitness at a single selected locus, while linked neutral sites are free to recombine away with a probability that grows with genetic distance from that locus. A haplotype heatmap shows each individual's ancestry across every site, a trajectory chart tracks the beneficial allele's realized frequency against the closed-form logistic curve p' = p(1+s)/(1+ps), and a valley chart plots diversity by chromosome position against the p^(r·d/s) hitchhiking approximation — the same genomic signature real scans use to find recent positive selection, such as around the human lactase-persistence gene.