Did STDs come from sheep?

It's likely that researchers will never come to an agreement about where syphilis originated and how it arrived in the Old World. The most widely accepted theory is that the venereal form of the disease arrived on the shores of Europe along with Christopher Columbus's crew, when they returned in 1493 from a journey to the New World. Indeed, although no cases of the disease seem to have existed in Europe before Columbus sailed to the New World, it had reached epidemic levels on the continent by around 1500. But in recent years, pre-Columbian skeletons -- such as those unearthed at the Hull friary in England -- have been found with distinctive signs of syphilis. Those skeletons have turned the nice, tidy picture of New World origins into a muddy mess.