An ecometric analysis of the fossil mammal record of the Turkana Basin.
Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of eastern Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago (Ma). We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change, and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 Ma have acted as a 'species factory', generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS Member (1.87-1.53 Ma), may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans.This article is part of the themed issue 'Major transitions in human evolution'.
Department of Geosciences and Geography, University of Helsinki, PO Box 64, Helsinki 00014, Finland Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066 Blindern, Oslo 0316, Norway Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin 10115, Germany mikael.fortelius@helsinki.fi.
Mikael
0000-0002-4851-783X
M
Fortelius
Department of Geosciences and Geography, University of Helsinki, PO Box 64, Helsinki 00014, Finland Helsinki Institute for Information Technology HIIT, PO Box 15600, Aalto 00076, Finland.
Indrė
I
Žliobaitė
Department of Geosciences and Geography, University of Helsinki, PO Box 64, Helsinki 00014, Finland.
Ferhat
F
Kaya
Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin 10115, Germany.
Faysal
F
Bibi
Departamento de Antropología, Universidad de Chile, Santiago, Chile.
René
R
Bobe
Turkana Basin Institute, Nairobi, Kenya Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA.
Louise
L
Leakey
Turkana Basin Institute, Nairobi, Kenya Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA.
Meave
M
Leakey
Department of Anthropology, Center for the Advanced Study of Hominid Paleobiology, The George Washington University, Washington, DC 20052, USA.
David
D
Patterson
Department of Geosciences and Geography, University of Helsinki, PO Box 64, Helsinki 00014, Finland.
Janina
J
Rannikko
Department of Palaeobiology, Swedish Museum of Natural History, PO Box 50007, Stockholm 104 05, Sweden.
Lars
L
Werdelin
D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D004777:Environment; D005580:Fossils; D015186:Hominidae; D007630:Kenya; D008322:Mammals / Q000502:physiology*; D008954:Models, Biological; D010163:Paleontology; D011891:Rain; D013696:Temperature
ecosystem change; fossil mammal; human origins; palaeoclimate; predictive modelling