Inspired by Trouble on the Homefront



One of the most essential reasons for having access to the wasteland and the remainder of humanity, apart from the obvious need for supplies and parts for the vault's aging life support apparatus, is to avoid collapse due to genetic stagnation and inbreeding. The number of Vault 101 residents has fallen significantly in the two centuries since it was sealed, implied heavily by various conversations prior to the Lone Wanderer's initial escape. If he/she successfully persuades the overseer to allow exterior access then the overseer himself will finally accept and openly admit that without external input, the vault's population will not remain genetically viable for more than a generation or so.
1. Is race mixing the best solution to avoid GS?

2. Is long-term race preservation (or isolation) similar to inbreeding? Does it lead to GS?