What does it mean when you have a situation where your
Consider two bi-allelic loci, A and B with alleles
A2 for A and
B2 for B. Negative values for D means that
A1 is more often associated with
B2 than expected. Similarly,
A2 is more often associated with
B1 than expected.
More info on Wikiedpia > Linkage Disequilibrium or on any intro book to population genetics (see here for recommendations). If there is anything in particular you do not about the definition of LD, feel free to ask a question by highlighting what is unclear to you.