OK, maybe cows aren’t so threatening now, but cattlelike beasts called bovids could be responsible for bringing tuberculosis to North America long before Europeans arrived. Rheumatologist Bruce Rothschild and paleontologist Larry Martin have found fossil evidence suggesting that this is true. They found that bovids with Asian origins like bison and bighorn sheep had bone lesions that are characteristic of tuberculosis. Bovids started spreading across the Americas about 75,000 years ago.

These same bovids may also be responsible for the extinction of mastodons. More then half of mastodon skeletons examined had tuberculosis related bone legions. The disease only started hitting the mastodons about 34,000 years ago. Since the bovids record of infection stretches back farther then that, they’re the suspects. Actually, the first documentation of this disease stretches back to a 500,000-year-old buffalo in China.

I think its amazing that a little bacterium can be so old and still kicking our asses. It’s had a lot of time to develop mutations to resist our defences.