If they be literal descendants of Aaron they have a legal right to the bishopric, if they are the firstborn among the sons of Aaron. Doctrine & Covenants 68:16
He lived so long because he married a young women when he was an old man and had lots of kids.
Coriantum took to wife, in his old age, a young maid, and begat sons and daughters;
wherefore he lived until he was an hundred and forty and two years old. Ether 9:24
