  In a comment on our manuscript "Strong selection significantly increases
epistatic interactions in the long-term evolution of a protein", Dr. Crona
challenges our assertion that shared entropy (that is, information) between two
residues implies epistasis between those residues, by constructing an explicit
example of three loci (say A, B, and C), where A and B are epistatically linked
(leading to shared entropy between A and B), and A and C also depend
epistatically (leading to shared entropy between A and C), so that loci B and C
are correlated (share entropy).
