TY  - JOUR
A1  - Trauth, Martin H.
A1  - Bergner, Andreas G. N.
A1  - Foerster, Verena
A1  - Junginger, Annett
A1  - Maslin, Mark A.
A1  - Schäbitz, Frank
T1  - Episodes of environmental stability versus instability in Late Cenozoic lake records of Eastern Africa
JF  - Journal of human evolution
N2  - Episodes of environmental stability and instability may be equally important for African hominin speciation, dispersal, and cultural innovation. Three examples of a change from stable to unstable environmental conditions are presented on three different time scales: (1) the Mid Holocene (MH) wet dry transition in the Chew Bahir basin (Southern Ethiopian Rift; between 11 ka and 4 ka), (2) the MIS 5-4 transition in the Naivasha basin (Central Kenya Rift; between 160 ka and 50 ka), and (3) the Early Mid Pleistocene Transition (EMPT) in the Olorgesailie basin (Southern Kenya Rift; between 1.25 Ma and 0.4 Ma). A probabilistic age modeling technique is used to determine the timing of these transitions, taking into account possible abrupt changes in the sedimentation rate including episodes of no deposition (hiatuses). Interestingly, the stable-unstable conditions identified in the three records are always associated with an orbitally-induced decrease of insolation: the descending portion of the 800 kyr cycle during the EMPT, declining eccentricity after the 115 ka maximum at the MIS 5-4 transition, and after similar to 10 ka. This observation contributes to an evidence-based discussion of the possible mechanisms causing the switching between environmental stability and instability in Eastern Africa at three different orbital time scales (10,000 to 1,000,000 years) during the Cenozoic. This in turn may lead to great insights into the environmental changes occurring at the same time as hominin speciation, brain expansion, dispersal out of Africa, and cultural innovations and may provide key evidence to build new hypotheses regarding the causes of early human evolution. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Paleoclimate
KW  - East Africa
KW  - Human evolution
KW  - Lakes
KW  - Sediments
Y1  - 2015
U6  - https://doi.org/10.1016/j.jhevol.2015.03.011
SN  - 0047-2484
VL  - 87
SP  - 21
EP  - 31
PB  - Elsevier
CY  - London
ER  - 
TY  - JOUR
A1  - Foerster, Verena
A1  - Vogelsang, Ralf
A1  - Junginger, Annett
A1  - Asrat, Asfawossen
A1  - Lamb, Henry F.
A1  - Schäbitz, Frank
A1  - Trauth, Martin H.
T1  - Environmental change and human occupation of southern Ethiopia and northern Kenya during the last 20,000 years
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Our understanding of the impact of climate-driven environmental change on prehistoric human populations is hampered by the scarcity of continuous paleoenvironmental records in the vicinity of archaeological sites. Here we compare a continuous paleoclimatic record of the last 20 ka before present from the Chew Bahir basin, southwest Ethiopia, with the available archaeological record of human presence in the region. The correlation of this record with orbitally-driven insolation variations suggests a complex nonlinear response of the environment to climate forcing, reflected in several long-term and short-term transitions between wet and dry conditions, resulting in abrupt changes between favorable and unfavorable living conditions for humans. Correlating the archaeological record in the surrounding region of the Chew Bahir basin, presumably including montane and lake-marginal refugia for human populations, with our climate record suggests a complex interplay between humans and their environment during the last 20 ka. The result may contribute to our understanding of how a dynamic environment may have impacted the adaptation and dispersal of early humans in eastern Africa. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Archeology
KW  - Paleoclimate
KW  - African humid period
KW  - Push factor
KW  - Adaption
KW  - Migration
KW  - Hunter-gatherers
KW  - Foragers
KW  - Pastoralism
KW  - Chew Bahir
Y1  - 2015
U6  - https://doi.org/10.1016/j.quascirev.2015.10.026
SN  - 0277-3791
VL  - 129
SP  - 333
EP  - 340
PB  - Elsevier
CY  - Oxford
ER  -