Let's look at another pedigree involving nail-patella syndrome and blood type.
What is different about this linkage relationship compared to the previous one that we examined?
The linkage of the same two alleles does not often persist throughout a species. Why?
Recombination
Migration and mating brings the disease and its new linked allele into another lineage
Lod Score Method
the log of the ratio of the probability of a given sequence of births based on some linkage distance to the same sequence of births without linkage
the value is called z or the lod score