Tibet became Buddhist relatively recently - during the middle ages I think, if not later. Prior to that, the 'religion' of Tibet was Bonism, practitioners were called Bon-Pos. This was very likely closely allied to other central Asian types of shamanic belief and practice. A certain amount of Bon symbolism etc found its way into Tibetan Buddhism, according to some scholars. Either way, it could be as Nicole suggested, that the basic shamanistic beliefs travelled with the two waves of immigration from Asia across the Bearing Strait into the Americas, where no doubt it mutated into many definite forms.
. A question: if aryuveda is superior to or even equal to mainstream medicine in it's effectiveness, why does Sai Baba give money to build hospitals which practice mainstream medicine? Unless we say he's one of the 'west-worshipping fools' - he could easily choose to fund aryuvedic centres.
Ha - yes, I guess so. I'm not against aryuveda BTW, or other forms of spiritual/natural/energy healing. But I tend to see them more as complimentary to mainstream treatment than a real alternative in many cases, esp.serious illnesses. Luckily, I am quite well, and in fact, even very well for a man of nearly 50 with my background. My only real troubles are a bit of rheumatism in the winter, and marginally high blood cholestorol. If I had a minor problem, I might well go to see a lady I know who is a practitioner of spiritual healing - if I felt I had something worse I'd definitely go to see a doctor.
The thing is ayurvedic and naturopathic systems find their forte in preventive medicine. A lifestyle fully in accordance with ayurvedic principles makes chances of major illnesses quite remote. Although it is not widely practiced, there are ayurvedic techniques for surgery - transplants, reconstructive surgery, skin grafts, etc. Details can be found in the Shushruta Samhita and resultant texts.