sentences:  Macrohaplogroup BT has been found in populations on every continent, since prehistoric times.It is the progenitor clade of the paternal haplogroups B and CT (all members of haplogroup B or CT are members of BT, but not all members of BT are necessarily members of B or CT).Sufficient data is not always available to determine which, if any, member haplogroup a Y chromosome in BT belongs to.