BULL, BUELL, BUL, BUHL, BUHLE, BUUL, and any other reasonable spelling variations are welcome to join the project. Only males have Y-chromosomes, so only males surnamed BULL (or variant) can participate. If you are female, you can have a male relative surnamed BULL (or variant) submit a sample for your line. To participate meaningfully, testees will need to share their direct male line ancestry back to the earliest known BULL (or variant), in the form of a pedigree (excluding living persons).