John Dehlin’s Mormon Stories essay on DNA and the Book of Mormon makes the following claim:
The Lenba [sic] are a group of 80,000 South Africans who claim Jewish heritage, practice many Jewish rituals, and claimed to be descended from small group of Middle Eastern men (perhaps as small as seven) who migrated to South East Africa 2,500 years ago and intermarried with the local women. Modern science backs their claim.
More than 50% of the Lemba Y-chromosomes are West Asian in origin. The DNA evidence suggests a migration date between 2,670 and 3,200 years ago, not far from their claim of 2,500. A study in 2000 found that a substantial number of Lemba men carry a particular haplotype of the Y-chromosome known as the Cohen modal haplotype (CMH), as well as a haplogroup of Y-DNA Haplogroup J found among some Jews, but also in other populations across the Middle East and Arabia. The genetic studies have found no Semitic female contribution to the Lemba gene pool. This indicates that Israelite men migrated to Africa in ancient times and took wives from among the local people while settling in new communities, just as their origin story suggests.
The similarities to the Book of Mormon premise are striking. Taking for granted that the Book of Mormon people existed in history, the migrations took place at the same time, the groups were of similar size, both had Israelite DNA, and likely intermarried with the locals. The big difference – abundant DNA evidence vs. no DNA evidence, and preserved Jewish culture and ritual vs. no preservation of Jewish culture or ritual.
First of all, the name of the tribe in question is Lemba, not “Lenba” [sic].
More important is whether the essay’s central claim is correct: there is “abundant DNA evidence” that the Lemba are descendants of ancient Israelites.
Using the primary research method of John Dehlin and his anonymous collaborator(s), when we consult Wikipedia we discover that the most recent scientific study does not support claims of Lemba descent from ancient Israelites on genetic grounds.
While it was not possible to trace unequivocally the origins of the non-African Y chromosomes in the Lemba and Remba, this study does not support the earlier claims of their Jewish genetic heritage. . . . It seems more likely that Arab traders, who are known to have established long-distance trade networks involving some thousands of kilometres along the western rim of the Indian Ocean, from Sofala in the south to the Red Sea in the north and beyond to the Hadramut, India and even China from about 900 AD, are more likely linked with the ancestry of the nonAfrican founding males of the Lemba/Remba.Soodyall (2013)
[O]ur results stress the limitations of using the above haplotype motifs as reliable Jewish ancestry predictors and show its inadequacy for forensic or genealogical purposes. . . . [W]hile the observed distribution of sub-clades of haplotypes at mitochondrial and Y chromosome non-recombinant genomes might be compatible with founder events in recent times at the origin of Jewish groups as Cohenite, Levite, Ashkenazite, the overall substantial polyphyletism as well as their systematic occurrence in non-Jewish groups highlights the lack of support for using them either as markers of Jewish ancestry or Biblical tales.Tofanelli et al (2014)
When blood groups and serum protein markers were used, the Lemba were indistinguishable from the neighbors among whom they lived; the same was true for mitochondrial DNA which represented the input of females in their gene pool. However, the Y chromosomes, which represented their history through male contributions, showed the link to non-African ancestors. When trying to elucidate the most likely geographic region of origin of the non-African Y chromosomes in the Lemba, the best that could be done was to narrow it to the Middle Eastern region. While no evidence of the CMH was found in the higher resolution study, no inferences can be made about their claims about being Jewish—all that can be said is the lineage commonly associated with the Cohanim is not found in the Lemba.Soodyall and Kromberg (2016)
So much for “abundant DNA evidence.”
Of course, had the author of the Mormon Stories essay merely consulted an actual scientist like Ugo Perego, they could have avoided this embarrassment.
Or they could have even read this short column by Michael Ash.
Or these observations by David G. Stewart, Jr. (pp. 113–116).
In fact, “modern science” does not back Lemba claims to Jewish heritage as purported in the Mormon Stories essay. What it has done is show that the picture is much more complicated than Dehlin’s simplistic and misinformed claims lead on.