Scientists say they have discovered in Turkey the most ancient evidence of tuberculosis in a 500,000-year-old human fossil.
The lesions are suggestive of TB
Experts had thought TB emerged several thousand years ago - based on the remains of mummies from Egypt and Peru.
The skeleton is of a young man believed to belong to the first human species to migrate out of Africa - Homo erectus.
The American Journal of Physical Anthropology details the find by a team from the US, Germany and Turkey.
Paleontologists spent decades prospecting in Turkey for the remains.
By looking at the skull, John Kappelman, professor of anthropology at the University of Texas, and his international team saw tell-tale signs of the disease.
They found a series of small lesions etched into the bone of the cranium whose shape and location they claim are characteristic of the Leptomeningitis tuberculosa, a form of TB that attacks the meninges lining of the brain.
The researchers believe the man's circumstances may have made him susceptible to the infection.
The dark-skinned Homo erectus, who migrated northward from low, tropical latitudes would have produced less vitamin D, which can weaken the immune system.
The body produces vitamin D when sunlight hits the skin. The skin pigment melanin - more abundant in darker skin - shields the body from the sun's rays, reducing damage from ultraviolet light, but also reducing vitamin D production.
Professor Kappelman said: "The production of vitamin D in the skin serves as one of the body's first lines of defences against a whole host of infections and diseases."
Dr Simon Mays, expert in human skeletal remains at English Heritage, said, until now, the most ancient case of TB recorded was from remains found in Italy dating back 5,000 years.
"This report suggests there was a case 450,000 years earlier than that. We would need very firm proof that the skull lesions described are indeed from TB and not something else."
TB is a disease of the respiratory system that is spread through the air after infected people cough or sneeze.
It usually attacks the lungs, but it can affect almost any part of the body.