ИСТИНА

The original study is devoted to morphological comparison of manual middle phalanges of the second to fourth rays of fossil inhabitants of Eurasia in the late Pleistocene. There are Neanderthals from Europe (La Ferrassie 1, Kiik-Koba 1), from Altai (caves Okladnikov and Chagyrskaya), the AMH from Eastern (Kostenki 14, Kostenki 8A&B, Sunghir 1) and Western Europe (Abri Pataud). Diaphyseal structure of tubular bones most often was evaluated from point of view of physical activity. Biomechanical analysis dominated in interpretation of the inner robusticity [1]. But it is accepted apriori that relative thickness of diaphyseal walls also depends on biological sex, age or from hereditary reasons or that it can have a taxonomic value. In the absence of larger tubular bones manual phalanges serve as a “model” for the postcranial skeleton overall. Their study allows to include in comparison of the representatives of different Eurasian groups the isolated finds from Siberia. MicroCT scanning was performed. Xradia software was used to create 3D models and virtual cross-sections, as well Avizo program was used for further segmentation of 3D images. The examination shows high diversity of inner robusticity of manual phalanges, which doesn’t seem to be dependent from the taxonomic attribution or sex and age of individuals. The high diversity was detected both for Neanderthals and for CroMagnons. Basing on the total area values of the midshaft section (TA) among Neanderthals the most volumentary diaphyses had males La Ferrassie 1 and Okladnikov 2. The highest and the lowest levels of inner robusticity (%CA) for Neanderthals represent women from Altai caves. The most thick walls in AMH and in the total studied sample had Kostenki 14 and the most (relatively) thin-walled AMH was Sunghir 1. In general, CroMagnons demonstrate the higher level of inner robusticity of manual phalanges in comparison with Neanderthals excepting one group of Altai Neanderthals. It could be proposed that morphology of manual phalanges of fossil humans reflect occupational hypertrophy of bone tissue connected with stone tools operating. Bouldering was another factor influenced hand morphology of inhabitants of rocky places, to whom belonged all studied Neanderthals from Dordogne, Crimea or Altai. But the majority of robust CroMagnons under the study inhabited open Eastern European plains. That means the common explanation of high inner robusticity as the developmental response to increased mechanical loading is questionable in this case. The earliest Eastern European AMH Kostenki 14 had exceptionally heavy skeleton. In particular, his distal and medial phalanges of the both hands demonstrate medullary stenosis [2] indicating systemic bone condition, probably, hereditary disease [3]. Recently genetic study of that young male who lived 38,700 to 36,200 years ago has discovered K14 origin from a meta-population, ancestral for many modern people as well for the Upper Palaeolithic humans [4]. His nuclear DNA contains longer tracts of Neanderthal DNA than present Europeans. The calculated approximate interbreeding time of K14 sapient ancestor and Neanderthal is around 54 thousands BP. The most robust or, correctly, thick walled Altai Neanderthals also had hybrid origin: they lived in contact area with Denisovans. Moreover, the early hybridization of their ancestors with anatomically modern humans somewhere in the Middle East was recently discovered [5]. It can be supposed that the inner robusticity in these morphological variants mainly depended on the origin of peoples and lesser from external influences. The tropical anatomically modern humans participated in origin of both Neanderthal and AMH robust forms are hypothetically best candidates as people with the thickest walls of tubular bones.