Answer:
They could use SNPs(Single nucleotide polymorphisms) of DNA, which are an anaylysis of chromosomes using high tech laser magnification. This SNPing allows scientist to more closely view specific genes in chromosomes that cause certain traits. It allows for a greater genetic mapping and could also be used to see mutations, if you know which chromosome to look at.
IDK, just an idea, SNPs were used to look at different species trait exhibition, I thought it might work for this if used properly.