origin and evolution of life
JACKSON K. NJAU Assistant Professor | Paleoanthropology
Research Associate, The Stone Age Institute and the Center for Research into the Anthropological Foundations of
Technology (CRAFT), Bloomington, Indiana.

Adjunct Professor, Department of Anthropology, Indiana University
The drilling program for scientific research that was carried out at Olduvai archaeological site in Tanza-
nia by the Olduvai Gorge Coring Project (OGCP) has yielded about 600 m of continuous core obtained
from ancient lakebeds. The core constitutes approximately 30 % of all cores from East African paleolake
and hominin sites (including Kenya and Ethiopia). OGCP was developed in 2013 by Jackson Njau, Kathy
Schick and Nick Toth (Earth and Atmospheric Sciences and The Stone Age Institute) with the goal of
obtaining high-quality cores, which are vital for the investigation of past climates and environments in
which early humans evolved. Along with parallel active and passive seismic studies conducted in the
area in collaboration with the King Abdullah University for Science and Technology (KAUST) scientists,
we have built a strong interdisciplinary research program bridging paleoanthropology and Earth sciences, making
OGCP one of the top drilling projects in Eastern Africa hominin sites. To date, twenty-seven scientists from eight
different countries and 14 labs (including IU) have been working on the project, focusing on different aspects of
the overall research including: sedimentology, X-Ray Fluorescence (XRF), argon-argon and paleomagnetic dating,
tephrastratigraphy, soil carbonate isotope ratios, phytoliths, pollen, diatoms, ostracods, organic geochemistry, pale-
ontology, archaeology, geophysics, and seismology.

We are beginning to get exciting results from core analyses revealing an unprecedented record of past environments
that might have influenced human evolution in the East African rift valley. Although the link between environmental
changes and human evolution faces many challenges, this research is changing longstanding views of early homi-
nin paleoenvironments at Olduvai, and offers new perspectives for reconstructing paleolandscapes and a holistic
understanding of hominin land use behaviors, climate history and basin evolution. The core record, which shows the
influxes of mudflows and vol-
canic materials (from the ad-
jacent Ngorongoro volcanoes)
and the unparalleled large,
deep and long-lived lake, sug-
gests that both climate mod-
ulated environmental change
and tectonic activities altered
the lake configuration and
shaped paleogeography and
hominin adaptations through
time. This ground-breaking
research is providing mod-
ern methods that address our
species’ humble beginnings,
and help us answer questions
about our origins.

28 | hgr

After successful completion of the
project’s phase I drilling (2014),
phase II seismic experiments (2015-
2017), and phase III, core sampling
at the NSF-funded National Lacus-
trine Core facility at the University
of Minnesota (2015-2017), OGCP
is now in phase IV of its research
program. Our goal here is to tie the
core stratigraphy to outcrop in or-
der to examine whether times of
significant environmental change
correspond to times of significant
technological or biological change
(observed in outcrop-derived fos-
sils and artifacts) during Bed I (~2
Ma), Lower Bed II–Upper Bed II
transition (~1.7 Ma), Bed III during
the Pleistocene Revolution (~1 Ma),
and Masek Beds (~0.4 Ma). We be-
gan this exercise by correlating the
volcanic ash layers and paleoenvi-
ronmental proxies archived in cores
to the archaeological-bearing units
in the outcrop. To this end, a series
of excavations was initiated at Old-
uvai Gorge in the summers of 2016
and 2017 in order to expose fresh
sections and recover more fossils
and stone artifact data. The excava-
tions targeted geological intervals
and sites that document key evo-
lutionary landmarks in the history
of our ancestors such as the transi-
tion from Homo habilis to H. erectus
and subsequently to anatomically
modern H. sapiens, the extinction
of early Homo and Australopithe-
cine hominins, and the first human
migration out of Africa.

hgr | 29