Good science. In spite of the protestations by LDS advocates below, this video holds up. The opposition's thin arguments do not.
What is clear from genetics is that Native Americans are not of Jewish origin. Most interestingly, other groups in the world who have claimed descent from diaspora Jews, even when somewhat mixed with local populations (in India, and Ethiopia, for example) do indeed carry those markers. Native Americans, on the otherhand, do not (except the few resulting intermarriage since Colonial times).
One point the video does not cover is that at least into the 1980's, Mormon baptism ritual featured "prophecying" which what tribe of Israel the newly baptized was from...no matter their family background. The were generally informed that they were either of the tribe of Ephriam or the tribe of Menasseh. According to the missionaries I had spoken to at the time (who had checked with their bishop), this was a prophecy regarding literal (not spiritual) familial descent. Likewise, Native American converts in the past were told they were originally Jews. Needless to say, that has not proven out genetically either. I do not know if they have foregone the practice as a result of this embarassing evidence.
It should be remembered that the Bering Strait land bridge disappeared long before the migration of Jews alleged in the Book of Mormon (who supposedly grew to utterly fill the land). So, we should be able to see genetic markers for people of Jewish descent throughout the Native American population. Of course, we do not. Thus trans-Siberian immigration across the Bering Strait (and/or back) does not change do anything to negate the evidence put forth in this video. The Native Americans-are-really-Jews thing (supposed lost tribes of Israel-though all were at Pentecost) was a popular theory in Joseph Smith's time (an American myth mixing 'the noble savage' with Anglo-Israelism of the old world). However, he made it the cornerstone of his new religion.
Of course, any thin excuse will be good enough for people who cannot admit that Joseph Smith's supposed translation of "The Joseph Smith Papyri" (which is just another copy of an Egyptian magical funerary text known as "The Book of the Dead") is a farce which proves him to be a false prophet. --- Smith claimed it was a text written in Abraham's own hand (which would also be difficult because the text was in Egyptian, though Abraham was Chaldean) including the near sacrifice of his son Isaac (which is not at all what the pictograph on the papyri portrays). At any rate, he had a habit of seeing what he wanted to see in anything he thought could justify his new teachings (such as polytheism, "God" was once a man, polygamous marraige in heaven, and that man can become a God over his own world).