[Mrs. Don-o]

But that was also OK under OT law: cousin marriage. Boaz was considered suitable to marry Ruth precisely because he was near kin.

Not denying, BTW, that kindred marriage can magnify the EXPRESSION OF recessive gene defects. Consider hemophilia, and Tay-Sachs.

[Cloverfarm]

Ruth wasn’t related to Boaz, her mother-in-law Naomi was.

But anyway, you are right about birth defects in small tight communities. We see and hear of them in the Mennonite groups here, too.