Walter W. Smith explains textual change to Ether 1:40–41 in RLDS authorized version.
Walter W. Smith, "Elders' Note-Book: Another Defense Gone," Saint's Herald 56, no. 40 (October 6, 1909): 943
Elders' Note-Book
ANOTHER DEFENSE GONE.
In the first chapter of the book of Ether in the Book of Mormon there is recorded the separation of the people of Jared and his brother from the tribes of men on the plains of Shinar at the time of the confusion and dispersion. It is there said that Jared asked his brother to go present their petition to God for direction. It is further recorded that God did wonderfully answer their cry. In the direction that God gave them they were told to gather together their flocks of every kind, and seed of every kind, and it is further written that the brother of Jared should gather his "families" and Jared should gather his family.
This would seem a very strange direction to be made to one so favored as the brother of Jared, and many have asked themselves, and often asked others why this should be recorded so. But an appeal to the original manuscript has relieved the situation materially, by the fact that in clear and bold hand. it is written "thy family," so that it is clear that the brother of Jared had only one family, though that family did consist of twenty-two souls.
How this error crept into the Book of Mormon we are not informed. It occurs in the first edition of 1830 on page 540, and has been repeated in every edition of the Book of Mormon except the "authorized edition," lately published and proof read from the original manuscript, where it will be read "thy family." Ether 1, page 716. When Orson Pratt,sr., made his references and annotations to the Book of Mormon he says in a footnote that "It seems that the brother of Jared had a plurality of families." But another error has been corrected, and with it another defense of polygamy is gone. One by one they fade away, as the light is turned on.—Walter W. Smith, in Sunday School Exponent, October 1, 1909.