Donald Yates claims in Anomalous Mitochondrial DNA Lineages in the Cherokee (self published in Cherokee DNA Studies: Real People Who Provied the Geneticists wrong) that a significant portion of Cherokee contain haplogroup T and because of the step-wise nature of the group, that this is evidence of a transoceanic dispersal.

There are a few problems with this claim:

  1. The scientific study upon which the claim was made has never been peer reviewed or published in a scientific journal. Peer review and publication in a scientific journal is viewed by most scholars as a minimum bar for making credible scientific claims. To date, the claim that haplogroup T supports a transoceanic migration event has not even reached the level of attention that geneticists have felt the need to address it (like they have done with X2a).
  2. Yates appears to have zero years of formal academic training in DNA genetic analysis, although he is the owner of a DNA testing company. His batchelor and masters degress are in English, his PhD in Classical Studies. He was a part time communications professor and then an assistant professor for four years “teaching public relations, speech, and other communication arts courses” (from his LinkedIn profile). Science is often performed by those with little initial academic training, but these individuals tend to eventually distinguish themselves through publication in peer reviewed journals (e.g., Zack Simpson was a high school drop out who has co-authored a number of scholarly scientific studies). As far as I can tell, Yates has authored or co-authored zero peer reviewed publications to date.
  3. At least some individuals used in the study are from Cherokee groups which had such poor ancestral claims that their petition for federal acknowledgement has been rejected (incidentally, rejected by Larry Echo Hawk, an LDS General Authority at the time).

    The petitioner’s own statements confirm the PF’s analysis of the evidence that Petitioner #227 is a recently formed group of individuals from diverse origins who claim to have Indian ancestry, but who have not documented those claims.

  4. If we are dealing with a genuine genetic signature, an unbiased analysis of 993 and 650,000 SNPs demonstrates that it is being absolutely dwarfed by many other genetic signatures which all seem consistent with a land-bridge migration. This doesn’t nullify his research per se (Yates was specifically seeking odd-ball signatures), but these other unbiased studies do undermine the standard narrative typically advanced in both official and unofficial LDS channels for nearly two centuries.

Note: The second of these points was compiled from a point made here (I believe it was made by /u/barefootcherokee, a Native American and former Mormon).