Abstract:
This thesis investigates Late Pleistocene climate–environment–hominin dynamics in the Indian
subcontinent, asking how large-scale climatic forcing influenced varied human-occupied ecosystems.
The theoretical framework distinguishes between instability (short, high-magnitude shocks) and
variability (orbitally paced monsoon fluctuations), aiming to explore how different parts of the
subcontinent's mosaic environments responded to climatic cyclicity. The investigation focuses on three
key questions to address this complex subject: What were the immediate-to-decadal impacts of the ~74
ka Toba (YTT) super-eruption in hominin-inhabited landscapes, and did they differ spatially? How did
orbital-scale monsoon variability reshape hominin ecosystems, and did habitat change mediate cultural
continuity and innovation? How did climatic variability govern expansions and extinctions of openhabitat
megafauna? To answer these questions, this thesis builds a transect of on-site, cross-disciplinary
investigations across Palaeolithic sites across the subcontinent including - Jwalapuram (southern India),
Tejpur (western India), and Dhaba (north-central India), with a fourth case examining fossil ostrich
eggshell (OES) from Motravulapadu (southern India). It integrates on-site stratigraphy and chronologies
with palaeopedology, plant-wax biomarkers, stable isotopes (bulk and compound-specific), and for
megafauna, OES isotopes alongside palaeoecological models (niche and circuit-theory connectivity).
The resulting evidence forms a coherent and holistic picture that challenges conventional climatedeterministic
narratives. The YTT super-eruption produced a brief, spatially heterogeneous perturbation
rather than the proposed volcanic winter, with rapid recovery in occupied settings explained by local
hydro-geomorphic buffering. More importantly, precessionally-paced monsoon variability did not map
linearly onto hominin-occupied habitats. At Tejpur, groundwater-fed systems maintained stable
woodland–grassland mosaics that facilitated long-term occupation and technological continuity. While
at Dhaba the MP→microlithic shift occurred under relatively humid MIS 3 conditions, pointing towards
demographic intensification and interaction rather than climatic deterioration as the driver of cultural
transition. The ostrich case study further illustrates context-specific responses in the case of a particular
megafaunal species, demonstrating that climate-mediated connectivity failure, not wholesale habitat
loss, set the stage for regional extirpation, with rising Homo sapiens populations likely tipping small,
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isolated demes over the threshold. These palaeoecological inferences align with the OES isotope dataset
and provide a process-based explanation for ostrich surprise occurrence in the deep south of the
subcontinent.
Collectively, these findings support the microhabitat-variability framework for the environmentally
heterogeneous Indian subcontinent, showing that hominin lifeways were organized around buffered
niches within shifting environmental mosaics, insulated from broader climatic variability and
instability. Precessionally-paced monsoon swings were filtered through hydrogeology and local
geomorphology, allowing sites like Tejpur, Jwalapuram, and Dhaba to sustain stable mosaics and longterm
hominin occupation. This demonstrates that microhabitat availability governs occupation patterns,
shapes behavioural evolution, and structures broader ecological dynamics. Ultimately, the thesis
underlines the importance of on-site investigation as such subtleties are invisible in distal archives. Only
on-site, cross-disciplinary investigation coupled with stratified context and chronologies with
multiproxy approaches, can resolve the human-scale pathways by which climate forcing influences
hominin behaviour and ecology. This approach transforms broad climate narratives into testable,
habitat-specific histories, explaining why the subcontinent functioned not merely as a corridor but holds
unique potential to answer globally-relevant questions in human-origins research. The thesis therefore
advocates designing new transects centred on Palaeolithic sites with stronger context and chronology
to test climate's role in the subcontinent's complex cultural landscape, the late persistence and extinction
of archaic hominins, episodes of introgression, complex hominin demography, and comparatively low
megafaunal extinction rates.
Prehistory