A new book casts doubts on the plausibility of a basic Book of Mormon claim, and it is polarizing members of the Church of Jesus Christ of Latter-day Saints.

In Losing a Lost Tribe: Native Americans, DNA, and the Mormon Church (Signature Books), research scientist Simon G. Southerton of Canberra, Australia, notes that none of the nearly 7,500 DNA-tested Native Americans shows any link to ancient Israel. More than 99 percent show an Asian heritage. The Book of Mormon, however, says that Israelites emigrated to the Americas 2,600 years ago, with the now-extinct Lamanites and Nephites becoming the ancestors of American Indians.

Southerton, a former LDS bishop, said he has received nearly 500 e-mails in the past five years from Mormons who are troubled by the DNA findings. Even some scholars at the Foundation for Ancient Research and Mormon Studies (FARMS) at Brigham Young University, the church's flagship school in Provo, Utah, concede the links between Native Americans and Asians are strong, and that a Middle Eastern contribution to the gene pool hasn't been established.

Staunch apologists of the faith deny that science disproves the faith's principal scripture. FARMS founder John W. Welch said such opposition has been circulating for nearly a century. "The DNA factor is just one more indication that people came from various places in the world," Welch said. "This is just one more piece in a very big and complicated and obscure archaeological and anthropological picture."

"The Book of Mormon never claimed to be an exclusive account of people of the Americas," said Daniel C. Peterson, editor of The FARMS Review.

But Southerton contends that several Book of Mormon passages, as well as statements by founder Joseph Smith, indicate ...