I suppose this was an ancient way to ensure genetic diversity and prevent pregnancy losses. There is already quite a bit of evidence that consanguinity leads to miscarriages [0].
Funnily enough, the strict endogamy among Indian caste groups actually leads to far less diversity. There have been many genetic studies on this from Dr. Lal's and Dr. Thangaraj's group at Center for Cellular and Molecular Biology.
bongoman37|4 years ago