40,000 years ago:

The Mycobacterium tuberculosis complex (The MTBC)

 

The smooth TB within M. prototuberculosis have a lower capacity to cause disease than bacteria of the MTBC. The MTBC evolved to become more effective at causing infection via mechanisms such as the acquisition of new genes coding for products that intensify cellular toxicity. There is still debate over the evolution and timing of spread of the MTBC from its ancestor. One study tentatively suggests the MTBC arose from M. prototuberculosis around 40 thousand years ago. This coincides with the period when modern human populations spread from the Horn of Africa, implying the disease co-migrated with humans out of Africa.