The two loci are on a chromosome, the more likely they will be separated by crossover events during gamete formation, and thus the frequency of recombination between loci on a chromosome can be used to measure the between those loci.

farther apart, genetic distance

Explanation:

The farther apart two loci are on a chromosome, the more likely they will be separated by crossover events during gamete formation, and thus the frequency of recombination between loci on a chromosome can be used to measure the genetic distance between those loci.

Genetic distance is a term used to describe the differences, if any, between the markers reported in one person's DNA results and those reported in a second person's results. It is the measure of the genetic divergence between species or between populations within a species, whether the distance measures time from common ancestor or degree of differentiation.