No offense taken in the least. I was truly seeking clarification of your premise.

Your assertion refers to truncated gene pool scenarios, as in the case of the FLDS, correct? Truncated gene pools occur in monogamous situations too, as the multitude of insular, orthodox religious groups: Anabaptists, Mennonites, Amish, insular Jewish cohorts...these populations manifest genetic defects attributable to a truncated gene pool after multiple generations of relative inbreeding [not necessarily consanguineous].