Person:

Alex, Bridget

This dissertation seeks to reconstruct the distribution of Neanderthals and modern humans in time and geographic space in order to better understand the nature of interactions between the groups. Because human fossils from the Late Pleistocene are so rare, the biogeography of Neanderthals and moderns is primarily inferred from radiocarbon dates of archeological industries, which are assumed to have been made by one group or the other. Following this methodology, I critically reviewed published radiocarbon dates and produced new dates from active excavations in three regions: the Levant, Balkans, and Northeast Europe. The resulting regional chronologies were compared to the distributions of Neanderthals and moderns predicted from interaction models of no overlap, rapid replacement, and prolonged coexistence. The scenario of prolonged coexistence was subdivided into models of integration, displacement, and avoidance.

Informative archaeological chronologies were produced for each region. In Northeast Europe, my new dates and site chronologies for Ciemna and Obłazowa Caves, Poland, suggest that the Middle Paleolithic ended before 45 kcalBP. In the greater region, a number of distinct assemblages appeared during Marine Isotope Stage 3 (MIS-3), but the duration and sequence of these industries is not well resolved due to the large uncertainties of the available chronometric dates. In the Levant, the dates and chronology reported here for Manot Cave, Israel, help to clarify the timing of Early Upper Paleolithic industries and test proposed migrations of modern humans between the Near East and Europe. Specifically, at Manot the Early Ahmarian industry was present by 46 kcalBP and the Levantine Aurignacian occurred between 37-35 kcalBP. However, it was the results from the Balkans that were most applicable to the interaction models proposed in this dissertation, and therefore most informative on the nature of Neanderthal-modern human interactions. The new dates from Pešturina, Hadži Prodanova, and Smolućka Caves, combined with published dates from other sites, suggest that Neanderthals and moderns overlapped for several thousand years in the Balkans. During this period of overlap the groups occupied distinct geographic zones, consistent with the models of prolonged coexistence by displacement or avoidance. The period of overlap ended by 39,000 calBP at the time of the Campanian Ignimbrite eruption and onset of the Heinrich Event 4 cold phase.

The timing of archeological industries in the Levant is central for understanding the spread of modern humans with Upper Paleolithic traditions. We report a high-resolution radiocarbon chronology for Early Upper Paleolithic industries (Early Ahmarian and Levantine Aurignacian) from the newly excavated site of Manot Cave, Israel. The dates confirm that the Early Ahmarian industry was present by 46,000 calibrated years before the present (cal BP), and the Levantine Aurignacian occurred at least between 38,000 and 34,000 cal BP. This timing is consistent with proposed migrations or technological diffusions between the Near East and Europe. Specifically, the Ahmarian could have led to the development of the Protoaurignacian in Europe, and the Aurignacian in Europe could have spread back to the Near East as the Levantine Aurignacian.

The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46–42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39–34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa.