I just read an article saying Joktan never went to Arabia

http://www.eifiles.cn/oo-en.htm

I've talked about descent from Joktan before.  On my Revised Chronology blog in the Queen of Sheba post, and the post about the Magi coming from Arabia.  And on my SolaScripturaChristianLiberty blog talking about Christianity in Pre-Islamic Arabia and Feminism in Pre-Islamic Arabia.  But this is a good opportunity to put my thoughts on this on record here.

This article first of all ignores that the Tower of Babel incident clearly took place before the events of Genesis 10, it's a prequel, and not it's the only place where Genesis is not strictly chronological, just look at Genesis 25.  But this site argues Joktan's clan must have broke off and headed East before the others reached Shinar.

Some Bible scholars have offered an opinion that Joktan migrated into Arabia
because two of his sons, Sheba and Havilah, have the same names as two tribes
in Arabia.  But those Arabian tribes are of Cushite descent in the lineage of Ham
and are not in the lineage of Shem at all (see Gen. 10:6-7).  Arabia is part of the
migration route to Africa, the land of Cush; therefore the first peoples in Arabia
were Cushite, in the lineage of Ham. 

(Many Biblical names may occur multiple times in the different genealogies but
that does not confirm a genealogical kinship; only the context can indicate that.)

Now I do agree about there being Cushites in Arabia.  The problem here is they ignore Ophir, there is no Ophir among the descendants of Cush, and Arabain traditions frequently linked Ophir to Sheba and Havilah.  And The Bible does the same.

It is the Sheba descended from Cush who wound up East of the Euphrates, in India, (The name of the Indian deity Shiva no doubt comes from Sheba).  In India there are mountains called the Hindu Kush and there was an ancient Kushan empire.  The Sheba and Dedan from Cush were sons of Ramah.  In Indian mythology there was also a Rama who had two sons, but their names were changed to Kusha and Lava.

The Dedan in Arabia was most certainly the Dedan of Jokshan son of Abraham by Keturah, because we know that Dedan was located firmly within what was promised to Abraham, and is fairly consistent with where Josephus says the sons by Keturah were settled.  The Abrahamic Sheba is the one I'm most uncertain where to place.

The Cushite Havilah is probably in the Near East but further north.

Many of the Arabian tribes descended from Joktan are known as Qahtanite tribes.  Mount Shepher is mount Zafar in Yemen.  The Yemeni Hadramaut kingdom descended from Joktan's son Hazarmaveth.

Joktan had 13 sons.  So I'm fine with arguing they aren't limited to Arabia, that some went to Africa via Havilah.  And some may have become Native Americans, giving Joktan's name to the Yucatan peninsula. 

Many Mormon scholars have a theory that the Jared who founded the Book of Mormon's Jaredites is the same as Jerah son of Joktan.  I think that could be what Smith intended given how he played with Biblical names.  The unnamed brother was probably meant to be the firstborn Almodad since he seems to be depicted as having Firstborn authority.

I don't believe the Book of Mormon however.  What I do believe is Native Americans came here via Asia and Alaska.  I also believe the deported northern Israelites contributed a great deal to the populations of Asia east of the Euphrates and the Native Americans.

So as far as this article's desire to make a point out of how massive the populations of the far east are.  Rebecca was told she'd be an ancestor of Thousands of Millions (that's Billions), Reuben was told in Deuteronomy 33 that his men would not be few.  And Ephraim was told he would become the fullness of the nations.

The Pre-Babel language was obviously Hebrew.