Abstract
The hypothesis of a connection between the onset (or intensification) of Northern Hemisphere Glaciation, the stepwise increase in African aridity (and climate variability), and an important mammalian (including hominin) species turnover is a textbook example of the initiation of a scientific idea and its propagation in science. It is, however, also an example of the persistent popularity of a hypothesis despite mounting evidence against it. A critical review of key publications on the topic and statistical re-analysis of key records of global ice volume and African climate leads to three conclusions: (1) The Northern Hemisphere Glaciation was a gradual process occurring between ∼3.5 and 2.5 Ma, not a single event at ∼2.8 Ma or at any other time. (2) A consistent stepwise (+/−0.2 Ma) transition toward greater aridity in Africa at ∼2.8 Ma does not exist; instead, there are regionally different, gradual transitions partly in connection with the intensification of the Northern Hemisphere Glaciation, but above all with the establishment of the tropical Walker Circulation after ∼2 Ma. (3) Mammalian (including hominin) species turnovers at this time also appear to have been gradual, rather than stepwise.
| Original language | English (US) |
|---|---|
| Article number | 107095 |
| Journal | Quaternary Science Reviews |
| Volume | 268 |
| DOIs | |
| State | Published - Sep 15 2021 |
Bibliographical note
Funding Information:This work was stimulated by ongoing discussions about the supposedly stepwise change in the aridity in Africa within the Hominin Sites and Paleolakes Drilling Project (HSPDP). Support has been provided by Germany Research Foundation ( DFG ) through the Priority Program SPP 1006 ICDP (SCHA 472/13 and /18, TR 419/8, /10 and/16) and the CRC 806 Research Project “Our way to Europe” Project Number 57444011. S.K.-B. received funding from an Open-Top Postdoc fellowship of the University of Potsdam . We thank Andrew Cohen, Alan Deino, Peter deMenocal, Henry Lamb, Rachel Lupien, Norbert Marwan, James M. Russell, and Elisabeth Vrba for inspiring discussions during the last fifteen years. Hominin site coordinates were obtained from the ROCEEH Out of Africa Database (ROAD), and the work of the data contributors and ROAD community is gratefully acknowledged. This is publication 40 of the Hominin Sites and Paleolakes Drilling Project. The data and code are available online at http://mres.uni-potsdam.de .
Funding Information:
This work was stimulated by ongoing discussions about the supposedly stepwise change in the aridity in Africa within the Hominin Sites and Paleolakes Drilling Project (HSPDP). Support has been provided by Germany Research Foundation (DFG) through the Priority Program SPP 1006 ICDP (SCHA 472/13 and /18, TR 419/8, /10 and/16) and the CRC 806 Research Project ?Our way to Europe? Project Number 57444011. S.K.-B. received funding from an Open-Top Postdoc fellowship of the University of Potsdam. We thank Andrew Cohen, Alan Deino, Peter deMenocal, Henry Lamb, Rachel Lupien, Norbert Marwan, James M. Russell, and Elisabeth Vrba for inspiring discussions during the last fifteen years. Hominin site coordinates were obtained from the ROCEEH Out of Africa Database (ROAD), and the work of the data contributors and ROAD community is gratefully acknowledged. This is publication ## of the Hominin Sites and Paleolakes Drilling Project. The data and code are available online at http://mres.uni-potsdam.de.
Publisher Copyright:
© 2021 Elsevier Ltd
Keywords
- Eastern africa
- Human evolution
- Onset of the northern hemisphere glaciation
- Paleoclimate dynamics
- Time-series analysis
Continental Scientific Drilling Facility tags
- HSPDP-BTB