McClintock's Jumping Genes: Maize Kernel Variegation

Barbara McClintock discovered transposable elements — "jumping genes" — by reading the spotted, streaky patterns on maize kernels as a developmental record. This simulator rebuilds that record from first principles: a colorless founder cell divides through a controllable number of mitoses, and at every division each still-colorless lineage has an independent chance to have its Ds element excise from the C1 pigment gene, permanently switching that entire branch of descendants to purple. Toggle Ac off to reproduce the classic no-transposase control (a solid colorless kernel), tune the excision rate and division count, and watch how early jumps paint large color blocks while late jumps paint fine speckling — live readouts track pigmented fraction, sector count and average sector size as the kernel grows.