Nonlinear detection of paleoclimate-variability transitions possibly related to human evolution

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doi: 10.1073/pnas.1117052108
Author(s): Donges, Jonathan F.; Donner, Reik V.; Trauth, Martin H.; Marwan, Norbert; Schellnhuber, Hans-Joachim; Kurths, Jürgens
Author Affiliation(s): Primary:
Potsdam Institute for Climate Impact Research, Potsdam, Germany
University of Potsdam, Germany
Volume Title: Proceedings of the National Academy of Sciences of the United States of America
Source: Proceedings of the National Academy of Sciences of the United States of America, 108(51), p.20422-20427. Publisher: National Academy of Sciences, Washington, DC, United States. ISSN: 0027-8424 CODEN: PNASA6
Note: In English. 70 refs.; illus., incl. charts, sketch map
Summary: Potential paleoclimatic driving mechanisms acting on human evolution present an open problem of cross-disciplinary scientific interest. The analysis of paleoclimate archives encoding the environmental variability in East Africa during the past 5 Ma has triggered an ongoing debate about possible candidate processes and evolutionary mechanisms. In this work, we apply a nonlinear statistical technique, recurrence network analysis, to three distinct marine records of terrigenous dust flux. Our method enables us to identify three epochs with transitions between qualitatively different types of environmental variability in North and East Africa during the (i) Middle Pliocene (3.35-3.15 Ma B.P.), (ii) Early Pleistocene (2.25-1.6 Ma B.P.), and (iii) Middle Pleistocene (1.1-0.7 Ma B.P.). A deeper examination of these transition periods reveals potential climatic drivers, including (i) large-scale changes in ocean currents due to a spatial shift of the Indonesian throughflow in combination with an intensification of Northern Hemisphere glaciation, (ii) a global reorganization of the atmospheric Walker circulation induced in the tropical Pacific and Indian Ocean, and (iii) shifts in the dominating temporal variability pattern of glacial activity during the Middle Pleistocene, respectively. A reexamination of the available fossil record demonstrates statistically significant coincidences between the detected transition periods and major steps in hominin evolution. This result suggests that the observed shifts between more regular and more erratic environmental variability may have acted as a trigger for rapid change in the development of humankind in Africa
Year of Publication: 2011
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Africa; Alkenones; Arabian Sea; Atlantic Ocean; Australopithecinae; Australopithecus; Benthic taxa; Biologic evolution; Cape Verde Rise; Cenozoic; Chordata; Clastic sediments; Climate change; Dust; Dynamics; East African Rift; East Mediterranean; Equatorial Atlantic; Europe; Eutheria; Hominidae; Homo; Indian Ocean; Isotope ratios; Isotopes; Italy; Ketones; Lake-level changes; Leg 108; Leg 117; Leg 160; Lower Pleistocene; Mammalia; Mediterranean Sea; Mediterranean region; Mid-Atlantic Ridge; Middle Pliocene; Neogene; Nonlinear processes; North Atlantic; O-18/O-16; ODP Site 659; ODP Site 662; ODP Site 721; ODP Site 722; ODP Site 967; Ocean Drilling Program; Organic compounds; Oxygen; Paleoclimatology; Paranthropus; Pleistocene; Pliocene; Primates; Quaternary; Sea-surface temperature; Sediments; South Atlantic; Southern Europe; Southern Italy; Stable isotopes; Statistical analysis; Tertiary; Tetrapoda; Theria; Time series analysis; Vertebrata
Coordinates: N180437 N183438 W0210134 W0210135
S012325 S012324 W0114421 W0114421
N164038 N164039 E0595147 E0595146
N163718 N163719 E0594746 E0594745
N340411 N340411 E0324331 E0324331
Record ID: 2014041959
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