New research shows that in some rare cases, mitochondrial DNA can be inherited from fathers!  Article here.  However, the Genetic Genealogist asserts that this occurrence is extremely rare and will not affect genealogical research.

Amongst the members of the Ralston Project, there are two primary haplogroups – R-M269 and I-M223.

Of the R-M269 members, two groups match (are related) and the remainder do not appear related. One of the matching groups, a subset of Ralstons from Renfrewshire have a very unique haplogroup – R-BY15421. The other matching group has not done further testing to refine their haplogroup. Their genealogy suggests a Scottish origin, though some trace to Ireland.

Of the I-M223 members, all but one are matches, suggesting they all descend from a common ancestor. A few have verified a haplogroup of I-L623 which would most likely mean all are I-L623. One member has received results of a Big-Y test which confirms a suspected further refinement to I-PH3906. Of those in the I-M223 matching group, confirmed genealogies can only trace back to the Ulster area of Ireland. Origins beyond that is unknow at this time, as to whether the family was from Scotland or England. This group (and matches) has the most variety of name spelling, including Ralston, Roulston, Rolston, Raulston, Rollston, etc.

The project is anxiously awaiting results from some English origin members, who will be submitting y-111 tests, to see where they will fit into the mix.