A Pleistocene palaeovegetation record from plant wax biomarkers from the Nachukui Formation, West Turkana, Kenya.
Reconstructing vegetation at hominin fossil sites provides us critical information about hominin palaeoenvironments and the potential role of climate in their evolution. Here we reconstruct vegetation from carbon isotopes of plant wax biomarkers in sediments of the Nachukui Formation in the Turkana Basin. Plant wax biomarkers were extracted from samples from a wide range of lithologies that include fluvial-lacustrine sediments and palaeosols, and therefore provide a record of vegetation from diverse depositional environments. Carbon isotope ratios from biomarkers indicate a highly dynamic vegetation structure (ca 5-100% C4 vegetation) from 2.3 to 1.7 Ma, with an overall shift towards more C4 vegetation on the landscape after about 2.1 Ma. The biomarker isotope data indicate ca 25-30% more C4 vegetation on the landscape than carbon isotope data of pedogenic carbonates from the same sequence. Our data show that the environments of early Paranthropus and Homo in this part of the Turkana Basin were primarily mixed C3-C4 to C4-dominated ecosystems. The proportion of C4-based foods in the diet of Paranthropus increases through time, broadly paralleling the increase in C4 vegetation on the landscape, whereas the diet of Homo remains unchanged. Biomarker isotope data associated with the Kokiselei archaeological site complex, which includes the site where the oldest Acheulean stone tools to date were recovered, indicate 61-97% C4 vegetation on the landscape.This article is part of the themed issue 'Major transitions in human evolution'.
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA kevinuno@ldeo.columbia.edu.
Kevin T
KT
Uno
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.
Pratigya J
PJ
Polissar
Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
Emma
E
Kahle
Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA Department of Anthropology, Rutgers University, Piscataway, NJ 08854, USA.
Craig
C
Feibel
Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794, USA CNRS, UMR 7055, Maison de l'Archéologie et de l'Ethnologie, Université Paris Ouest-Nanterre La Défense, Nanterre, Cedex 92023, France.
Sonia
S
Harmand
CNRS, UMR 7055, Maison de l'Archéologie et de l'Ethnologie, Université Paris Ouest-Nanterre La Défense, Nanterre, Cedex 92023, France.
Hélène
H
Roche
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
Peter B
PB
deMenocal
D000818:Animals; D001106:Archaeology; D044822:Biodiversity; D005075:Biological Evolution; D015415:Biomarkers / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis; D017753:Ecosystem; D005580:Fossils; D015186:Hominidae; D007630:Kenya; D010163:Paleontology; D010944:Plants
D015415:Biomarkers; D002247:Carbon Isotopes
Acheulean tools; carbon isotope; hominin palaeoenvironment; leaf wax; pedogenic carbonate