Paleopathology of human tuberculosis: review and focus on the hypothetical oldest evidence on the Homo erectus from Turkey

Human tuberculosis (TB) has been considered for a long time as a model of animal infection transmitted to humans, resulting from cattle domestication at the Neolithic period. A decade ago, studies of molecular phylogeny of the Mycobacterium tuberculosis complex (MTBC) has challenged this dogma, suggesting that this human infection could be old emerging ca 2-3 Myrs ago. Paleopathological study would then be able to predate the earliest evidence of animal husbandry.

Presumed morphological changes attributed to TB were described by Kappelman and coworkers on the endocranial surface of the Kocabaş fossil skull attributed to Homo erectus (Kappelman et al. 2008) thought to be half-million-years-old at that time. However, the validity of this diagnosis was refuted by Roberts and coworkers (Roberts et al. 2009) and new dates were recently obtained for this fossil at 1,6 – 1,2 Ma (Lebatard et al. 2014) in the context of a Franco-Turkish pluridisciplinary research program (“First Homo in Turkey” PICS 2016-2018). The Kocabaş fossil is thus one of the oldest hominins known out of Africa, with the Dmanisi ones dated to 1.8 Ma in Georgia (Vialet et al. 2018).

In order to bring new light on the pathological aspect of this fossil, we planned complementary studies on human and animal fossils by new macromorphological and 3D imaging analyses. Micro-CT analysis can be contributive here to clarify the morphology of the endocranial aspects especially by virtual 3D reconstructions focusing on their possible inner extension and on soft tissue imprints. So far, the most ancient paleopathological cases of human TB authenticated by micro-CT, lipid biomarkers and aDNA are predating domestication in Fertile Crescent (Early PPNB-Syria) and are dated at ca. 11 kyrs BP (Baker et al. 2015; Coqueugniot et al. 2015)