It has long been suspected that there may have been conversions between TRAUB / TROUP and STRAUB / STROUP. We now have proof of such a conversion, in at least one case.

DNA testing has revealed a tight genetic match between a TROUPE descendant of John Peter TRAUB / TROUP of Perry Twp., Snyder Co., PA:
http://dgmweb.net/genealogy/FGS/Tr/TroupJohnPeter-AnnaMariaH...

and a STRAUB descendant of Jonathan Francis STRAUB / STROUP of Chapman Twp., Snyder Co., PA:
http://dgmweb.net/genealogy/FGS/Stra/StraubJonathanFrancis-C...

Their match is at the level of 37 markers out of 37, indicating they have a 99% probability of having a common ancestor within nine generations:
http://dgmweb.net/genealogy/DNA/Straub/StraubDNA-results-HgI...

This match has prompted me to include TRAUB / TROUB / TROUP / TROUPE under the umbrella of the STRAUB DNA Project:
http://dgmweb.net/genealogy/DNA/Straub/StraubDNA.shtml

Test subjects for the project must be male and surnamed TRAUB / TROUB / TROUP / TROUPE or some other variation. If you have any questions, please feel free to contact me.

Diana Gale Matthiesen, Administrator
STRAUB Y-chromosome DNA Surname Project

Disclaimer: I am a volunteer administrator (I'm retired, and genealogy is my hobby). I have no financial connections whatsoever with the testing company.