A publication of the Archaeological Institute of America
Analysis of Homo erectus skeletal remains suggests the disease yaws had its origins in Middle Pleistocene Africa 1.5 million years ago. Before now the earliest known evidence of the bacterial affliction was a skeleton from the Mariana Islands in the Pacific dated ca. A.D. 850.
Yaws is one form of treponematosis, which also includes the diseases pinta, venereal syphilis, and endemic syphilis or bejel. It occurs in tropical regions and begins as an inflammatory lesion through which bacteria enter the body. The bacteria then spread, causing extensive bone destruction as well as new bone formation.
Israel Hershkovitz of Tel Aviv University and Bruce Rothschild and Christine Rothschild of the Arthritis Center of Northeast Ohio examined an H. erectus skeleton in the Kenya National Museum, finding deposits of new bone up to seven millimeters thick on arm and leg bones, a condition diagnosed by the skeleton's discoverers as having resulted from an excess of vitamin A. The location and amount of deposits, say the researchers, are indicative of yaws. Similar bone deposits on an H. erectus femur dated ca. 500,000 years ago from Venosa, in southern Italy, suggest that when early humans spread out from Africa they took yaws with them.