I have been thinking about Wyeast 1056 ever since Chris Large at the University of Washington replied to my inquiry. Chris is a graduate student on the yeast research team that is studying the different sources of this strain in use. Here is part of his reply:
"Furthermore, we were a little thrown off up until recently by some sequencing of BRY-97 that placed it outside of the American brewing yeast strains (we now think that sequencing was of a contaminant). We have since received a copy of the original deposited strain from Tobias. I'm still in the process of finishing the analysis on it, but it appears that the strain is really closely related to Wyeast1056. As well, we got some info from Tobias about BRY-97: "BRY-97 was re-isolated from a brewery that originally bought Siebel’s BRY-96. The new isolate had some superior characteristics e.g. better flocculation. That is why we decided to use this isolate to commercialize as a dry yeast and call it BRY-97." I wouldn't be very surprised if Wyeast1056 is in fact a derivative of BRY-97, which is pretty neat (more analysis needed though). "
The quoted verbiage is from Tobias Fischborn. Tobias is a senior research scientist at Lallemand. I am beginning to believe that BRY-97 is actually Sierra Nevada's culture, which is why BRY-97 matches Wyeast 1056 genetically so well. It is well-known that Sierra Nevada started with BRY-96. The head brewer has even mentioned it (he referred to it as culture #96). However, he also mentioned that Sierra Nevada now uses their own variant that is the result of selective pressure in their environment. We also know that 1056 came from Sierra Nevada. To have that close of a genetic match has to mean that BRY-97 is Sierra Nevada.