Christopher L. Hill

Identification of Immunoreactive Material in Mammoth Fossils

The fossil record represents a history of life on this planet. Attempts to obtain molecular information from this record by analysis of nucleic acids found within fossils of extreme age have been unsuccessful or called into question. However, previous studies have demonstrated the long-term persistence of peptides within fossils and have used antibodies to extant proteins to demonstrate antigenic material. In this study we address two questions: Do immunogenic/antigenic materials persist in fossils? and; Can fossil material be used to raise antibodies that will cross-react with extant proteins? We have used material extracted from a well-preserved 100,000–300,000-year-old mammoth skull to produce antisera. The specificity of the antisera was tested by ELISA, western blotting, and immunohistochemistry. It was demonstrated that antisera reacted specifically with the fossils and not the surrounding sediments. Reactivity of antisera with modern proteins and tissues was also demonstrated, as was the ability to detect evolutionary relationships via antibody–antigen interactions. Mass spectrometry demonstrated the presence of amino acids and specific peptides within the fossil. Peptides were purified by anion-exchange chromatography and sequenced by tandem mass spectrometry. The collagen-derived peptides may have been the source of at least some of the immunologic reactivity, but the antisera identified molecules that were not observed by mass spectrometry, indicating that immunologic methods may have greater sensitivity. Although the presence of peptides and amino acids was demonstrated, the exact nature of the antigenic material was not fully clarified. This report demonstrates that antibodies may be used to obtain information from the fossil record.

Geologic contexts of the Acheulian (Middle Pleistocene) in the Eastern Sahara

The Bir Tarfawi and Bir Sahara East region of northeast Africa contains sedimentary remnants associated with Acheulian artifacts. The geology of these localities can be used to help examine paleobiogeographic and taphonomic contexts and paleoclimatic chronologies related to Middle Pleistocene hominids. Recognized by the presence of handaxes, Acheulian occurrences in the Eastern Sahara have been found with paleosols, cemented gravels, and tufas, and are often found as deflationary lags. In the Tarfawi region, handaxes were found embedded in sands overlain by carbonates, embedded in limestones, and in deflated contexts. These Acheulian sites likely date to before 300 ky B.P. The lithostratigraphic sequences indicate that paleoclimatic conditions in the Sahara during the Pleistocene were wetter than in the Holocene. The geologic context (stratigraphy, sedimentology, dating) of the Acheulian in the Eastern Sahara seems to indicate wet paleoclimatic intervals during the Pleistocene when biogeographic conditions were favorable for hominid habitation in the region.

Pleistocene Deposits in the Southern Egyptian Sahara: Lithostratigraphic Relationships of Sediments and Landscape Dynamics at Bir Tarfawi

Abstract The sedimentological and lithostratigraphic record from north-central Bir Tarfawi documents the presence of Pleistocene basin-fill deposits. Three topographic basins were created as a result of deflation during climate episodes associated with lowering of the local groundwater table. In each case, the three deflational basins or topographic depressions were subsequently filled with sediments; these basin aggradations coincided with changes from arid climate conditions to wetter conditions and a rise in the groundwater table. The oldest and highest sedimentary remnant is associated with Acheulian artifacts and may reflect spring-fed pond and marsh conditions during a Middle Pleistocene wet climate episode. Lithofacies for a lower stratigraphic sequence (the “White Lake”) documents deposition in a perennial lake that varied in extent and depth and is associated with Middle Paleolithic artifacts. A third episode of deflation created a topographic low that has been filled with Late Pleistocene sediments that are associated with Middle Paleolithic artifacts and fossil remains. Lateral and vertical variations in the lithofacies of this basin-fill sequence and the sediments of the “grey-green” lake phases provide a record of changing hydrologic conditions. These hydrologic conditions appear to reflect variations in water-table levels related to groundwater recharge and, at times, local rains.

The Geoarchaeology of Lake Michigan Coastal Dunes

There is a lot to recommend in this interdisciplinary monograph, with its goal of formulating a time-space framework that connectsgeological andbiologicalprocesses and human activity to the presence of coastal archaeological sites. Its significance goes beyondacontribution to theHolocenegeomorphic evolution and geoarchaeology of the North American Great Lakes. This work addresses a basic and important question: What determines the patterns of variability observed in the archaeological record, human behavior, or natural taphonomic processes? The authors have succeeded in demonstrating the value of integrating a thorough understanding of landscape processes with the patterns of variability in the archaeological record. Along the western coastline of Michigan are dunes that in some cases contain artifacts. This study examines the evolution of Lake Michigan coastal dunes, their age and

Alluvial Stratigraphy and Geoarchaeology in the Big Fork River Valley, Minnesota: Human Response to Late Holocene Environmental Change

Abstract The Late Quaternary geomorphology and stratigraphy of the Big Fork River valley, within the Rainy River basin of northern Minnesota, reveals evidence of prehistoric human interaction with late Holocene riverine environments. By 11 000 14C BP, deglaciation made the region inhabitable by human groups using Clovis artefacts. Human habitation would also have been possible during the Moorhead low-water stage of glacial Lake Agassiz, starting at 10 500 14C BP. Near its confluence with the Rainy River, the valley floor of the Big Fork valley consists of a floodplain complex and two terraces. The multi-component stratified Hannaford site is situated within the active floodplain. Overbank deposits contain artefacts in primary context, whereas artefacts within the point bar deposits are in secondary archaeological context; these deposits are associated with changing alluvial settings as the river moved eastward. Aggradation of the valley fill beneath the lowest surface (T0, floodplain complex) began by 3000 years ago and is associated with human activities focused on seasonal fishing and the use of riparian resources from 1300 to 650 14C BP.

E-86-4: Artifacts in Marsh-Related Sands of the Lower Lake (Grey Phase 3)

Site E-86-4 was discovered while surveying the margins of the sedimentary remnant associated with E-86-2 and E-86-3. The site is 150 m northeast of E-86-2, 100 m southeast of E-86-3, and 500 m southwest of E-87-3 (Fig. 29.1). It is slightly lower in elevation than E-86-3, between 245–246 m asl, and is at the same elevation as the artifacts recovered from similar sands in Tr. 7/86, east of E-86-2 (Fig. 3.32). E-86-4 consisted of a large, diffuse scatter of lithic artifacts on the eastern side of a sedimentary remnant made up of various deposits associated with the initial stages of a Pleistocene lake. A preliminary description of E-86-4 suggested that the artifact accumulation was a result of multiple reoccupations of short-term, unspecialized living-sites (Wendorf et al. 1987b: 59). The exposed artifacts were embedded in and eroding out of loose sands in an apparent deflational “window” (Fig. 29.1).

E-87-2: A Site in Lake-Margin Deposits of the Green Phase

In the northern part of Section BT-B of Bir Tarfawi, east of and adjacent to the plateau escarpment, there is a large (ca. 200 × 200 m) remnant of lacustrine and aeolian sediments. Site E-87-2 is on the southwestern edge of these sediments (Fig. 30.1). The Middle Paleolithic sites associated with the Sand Pan (E-86-1, E-87-1 and E-87-4) are west of the edge of the escarpment, while to the south and east is the sedimentary remnant containing E-87-3 (Fig. 3.23).