Location of Ac changes due to transposition

McClintock used classical linkage analysis with genetic testers and morphological markers to show that the 1 yellow: 1 variegated ratio occurred when Ac was on a non-homologous chromosome to chromosome 9. Sometimes Ac transposed to chromosome 9, then there was no longer a 1:1 ratio. Deviations from a 1:1 ratio and linkage to other markers confirmed that the Ac element had moved to a different location.