Mormons:where did the American Indian originate?

In the last decade scientists from several research groups had tested the mitochondrial DNA of over 2000 American Indians from about a hundred tribes tered over the length of the Americas. It soon became apparent to me that about 99% of their female lineages were brought into the Americas in excess of 12,000 years ago. Almost all of these lineages are most closely related to those of people in Asia, particularly in southern Siberia near Mongolia. Several tribes in Mesoamerica (which included Aztecs and Mayans) had been tested and all but a couple of individuals out of about 500 had mitochondrial DNA of Asian origin. How is this possible if they came from Israel and the tribe of Joseph... Please explain.. Jim