Jonathan Reeves

Pleistocene footprints show intensive use of lake margin habitats by Homo erectus groups

Reconstructing hominin paleoecology is critical for understanding our ancestors’ diets, social organizations and interactions with other animals. Most paleoecological models lack fine-scale resolution due to fossil hominin scarcity and the time-averaged accumulation of faunal assemblages. Here we present data from 481 fossil tracks from northwestern Kenya, including 97 hominin footprints attributed to Homo erectus. These tracks are found in multiple sedimentary layers spanning approximately 20 thousand years. Taphonomic experiments show that each of these trackways represents minutes to no more than a few days in the lives of the individuals moving across these paleolandscapes. The geology and associated vertebrate fauna place these tracks in a deltaic setting, near a lakeshore bordered by open grasslands. Hominin footprints are disproportionately abundant in this lake margin environment, relative to hominin skeletal fossil frequency in the same deposits. Accounting for preservation bias, this abundance of hominin footprints indicates repeated use of lakeshore habitats by Homo erectus. Clusters of very large prints moving in the same direction further suggest these hominins traversed this lakeshore in multi-male groups. Such reliance on near water environments, and possibly aquatic-linked foods, may have influenced hominin foraging behavior and migratory routes across and out of Africa.

Landscape scale heterogeneity in the east Turkana ecosystem during the okote member (1.56 - 1.38 Ma)

Placing the biological adaptations of Pleistocene hominins within a well-resolved ecological framework has been a longstanding goal of paleoanthropology. This effort, however, has been challenging due to the discontinuous nature of paleoecological data spanning many important periods in hominin evolution. Sediments from the Upper Burgi (1.98-1.87 Ma), KBS (1.87-1.56 Ma) and Okote (1.56-1.38 Ma) members of the Koobi Fora Formation at East Turkana in northern Kenya document an important time interval in the evolutionary history of the hominin genera Homo and Paranthropus. Although much attention has been paid to Upper Burgi and KBS member deposits, far less is known regarding the East Turkana paleoecosystem during Okote Member times. This study pairs spatially-resolved faunal abundance data with stable isotope geochemistry from mammalian enamel to investigate landscape-scale ecosystem variability during Okote Member times. We find that during this period 1) taxa within the East Turkana large mammal community were distributed heterogeneously across space, 2) the abundance of C3 and C4 vegetation varied between East Turkana subregions, and 3) the Karari subregion, an area with abundant evidence of hominin stone tool manufacture, had significantly more C3 vegetation than regions closer to the central axis of the Turkana Basin (i.e., Ileret and Koobi Fora). These findings indicate that the East Turkana paleoecosystem during the Okote Member was highly variable across space and provided a complex adaptive landscape for Pleistocene hominins.

Homo erectus paleoecology and behavior based on 1.5 million year old footprints from northwestern Kenya

Leprosy is one of the few specific infectious diseases that can be studied in bioarchaeology due to its characteristic debilitating and disfiguring skeletal changes. Leprosy has been, and continues to be, one of the most socially stigmatising diseases in history, over-riding all other aspects of social identity for the sufferers and frequently resulting in social exclusion. This study examines the stable isotopic evidence of mobility patterns of children, adolescents, and young adult individuals with the lepromatous form of leprosy in Medieval England (10 th –12 th centuries AD) to assess whether the individuals buried with the disease were non-locals, possibly from further afield. Enamel samples from 19 individuals from the St. Mary Magdalen Leprosy Hospital, Winchester (UK) were selected for strontium ( 87 Sr/ 86 6U DQG R[\JHQ į 18 O) stable isotope analysis based on age at death (<30 years), the presence of bone changes associated with lepromatous leprosy, and the underlying geology of their burial locations. The results from these data indicate that the St. Mary Magdalen Leprosy Hospital received an almost equal mixture of local and non-local individuals from further afield, including early pilgrims. At present, the St. Mary Magdalen Leprosy Hospital is the earliest dedicated leprosaria found within Britain and mobility studies such as these can help elucidate and test some of the broader historical notions and identities associated with the movements of those infected with the disease in Medieval England.