At both the April and October 1916 General Conferences James E. Talmage spoke of the Lost Ten Tribes:
Talmage also said something else at the October 1916 Conference. The following is from the
Old Testament student manual at lds.org.
Then in October conference Elder Talmage spoke again of the lost tribes and made this remarkable prediction: “The ten tribes shall come; they are not lost unto the Lord; they shall be brought forth as hath been predicted; and I say unto you there are those now living—aye, some here present—who shall live to read the records of the Lost Tribes of Israel, which shall be made one with the record of the Jews, or the Holy Bible, and the record of the Nephites, or the Book of Mormon, even as the Lord hath predicted” (in Conference Report, Oct. 1916, p. 76; emphasis added).
I could just leave that quote hanging there, but I can't resist commenting.
One, it makes the basic mistake of naming both an event and a time, so it's easily proven wrong. What they teach in Prophetry 101 is you should do it like this: "This generation shall see great things never before seen but we can't reveal exactly what." Or: "The lost tribes will come floating back on an iceberg but we can't reveal exactly when." Either one can't be disproven, but Talmage's can simply be waited out, and I think we're just about there, since even babies at the conference would be close to a hundred years old now.
Can't really blame him, though. Jesus, among other prophets, made the same mistake in Mark 31:30: "Verily I say unto you, that this generation shall not pass, till all these things be done." It's just such a tempting way to make one's listeners feel special.
But also, in one sense, the prediction has come true. A quick google turned up this, for example:
"Y chromosomes traveling south: the cohen modal haplotype and the origins of the Lemba--the "Black Jews of Southern Africa." Needless to say, there has been all kinds of religious foofarah around the Lemba people, but the bottom line is that it looks like DNA
can link genetically similar people to other related populations.
I think that points up the difference between a view of the world which puts reality/nature first, and which puts the word of people first.
We may discover in the future that DNA is as much pseudoscience as phrenology, but for now, it seems a genuine way of tracing genetics, so it's an actual, real, testable way of finding the "records" of a "lost tribe" like the Lemba.
The result of that knowledge, in my opinion, isn't much more than: "well, that's a cool bit of trivia concerning human migration." And of course Talmage was just lucky--I'm sure he didn't actually mean DNA and was thinking instead of another book like the Bible or the Book or Mormon, and DNA testing actual disproves more of the LDS beliefs than it proves. But still, it's something we didn't know before, thanks to evidence discovered by a lot of smart people doing a lot of hard work.