There is some crossing over of DNA during meiosis when the chromosomes segregate. So, alleles on the same chromosome can be separated and go to different daughter cells. There is a greater probability of this happening if the alleles are far apart on the chromosome, as it is more likely that a cross-over will occur between them. The relative distance between two genes can be calculated using the offspring of an organism showing two linked genetic traits. The percentage of offspring where the two traits do not run together is noted. The higher the percentage of offspring showing both traits, the closer on the chromosome the two genes are. 