Brian of nzolivers.com is descendant through John’s son Andrew.

Information from “McCaul Family Scotland” compiled in 1991 by Marcia Barbara (Barbara) McCaul, Canada (b. 1932, d. 2002). Barbara was the great-great grandaughter of Gilbert McCaul (b. 1765) and Janet McFarlan (b. 1770). Brian of nzolivers.com is the great-great-great grandson of Gilbert and Janet.

Sourced from, “Pre-1855 Gravestone Inscriptions for Carrick, Ayrshire”
https://familysearch.org/eng/library/fhlcatalog/su...e+inscriptions+in+Ca