2 results
6 - Seasonality and long-term change in a savanna environment
-
- By Susan C. Alberts, Department of Biology Duke University Box 90338 Durham NC 27708 USA; Institute for Primate Research National Museums of Kenya Nairobi Kenya, Julie A. Hollister-Smith, Department of Biology Duke University Box 90338 Durham NC 27708 USA, Raphael S. Mututua, Amboseli Baboon Research Project Amboseli National Park Kenya; Institute for Primate Research National Museums of Kenya Nairobi Kenya, Serah N. Sayialel, Amboseli Baboon Research Project Amboseli National Park Kenya; Institute for Primate Research National Museums of Kenya Nairobi Kenya, Philip M. Muruthi, African Wildlife Foundation Box 48177 Nairobi Kenya, J. Kinyua Warutere, Amboseli Baboon Research Project Amboseli National Park Kenya; Institute for Primate Research National Museums of Kenya Nairobi Kenya, Jeanne Altmann, Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544 USA; Department of Conservation Biology Brookfield Zoo Brookfield, IL USA; Institute for Primate Research National Museums of Kenya, Nairobi, Kenya
- Edited by Diane K. Brockman, University of North Carolina, Charlotte, Carel P. van Schaik, Universität Zürich
-
- Book:
- Seasonality in Primates
- Published online:
- 10 August 2009
- Print publication:
- 17 November 2005, pp 157-196
-
- Chapter
- Export citation
-
Summary
Introduction
The emergence and spread of savannas in Africa during the past five million years is often cited as a major factor in hominid evolution. Tropical savannas are different from forests in having less rainfall, which is strongly seasonal and often very unpredictable, even within seasons (Bourliere & Hadley 1983; Solbrig 1996). Human ancestors are thought to have moved into savannas as a response to cooling and drying climates, and the exigencies of the savanna environment – including the marked seasonal changes in plant food availability – are often cited as key selective pressures shaping the hominid lineage (see reviews and references in Foley [1987, 1993], Potts [1998a, 1998b], Klein [1999], and Chapters 4, 5, and 17). This scenario invites a careful examination of responses to seasonality in extant savanna-dwelling primates.
Like most vertebrates, the large majority of primate species exhibit reproductive seasonality that reflects the seasonality of their habitats (see review in Chapter 11). Indeed, among savanna-dwelling primates, there are only two exceptions to the rule of seasonal reproduction: humans and baboons (genus Papio). This shared characteristic – the ability to reproduce throughout the year in seasonal environments – may be related to the extraordinary success of these two genera. While only humans (and their commensals) have spread across the globe, baboons have achieved a nearly continental distribution in Africa.
Provenance of Kanjera Fossils by X-Ray Fluorescence and Ion Microprobe Analyses
- A. M. Kinyua, T. Plummer, N. Shimizu, W. Melson, R. Potts
-
- Journal:
- Advances in X-ray Analysis / Volume 35 / Issue B / 1991
- Published online by Cambridge University Press:
- 06 March 2019, pp. 1165-1173
- Print publication:
- 1991
-
- Article
- Export citation
-
XRF and Ion mfcroprobe analyses of fossils of known and uncertain provenance from the Lower-Middle Pleistocene locality of Kanjera. Kenya, are reported. The goal of this study was to develop a nondestructive technique of provenancixig fossils, which could be applied to the Kanjera sample. The fossils of known provenance were collected in the excavations of the 1987 Smithsonian Expedition. Three fossils of uncertain provenance, two specimens of Theropithecus oswaldi and a hominid fossil, were analyzed as test cases.
Both qualitative and quantitative XRF analyses of Kanjera fossils were carried out. In the qualitative analysis, the elemental peak areas from each fossil's XRF spectrum were calculated and normalized to the peak area of the incoherently scattered radiation. Results of the analysis showed that fossils from the Lower-Middle Pleistocene Kanjera Beds, for the most part, had higher levels of yttrium (Y) and zirconium (Zr) than those of the younger Apoko (Ap) Bed. black cotton soil (BCS) and modem bones (MD). The relative concentrations of uranium (U) v strontium (Sri and thorium (Th) were diagnostic of the Kanjera Bed of origin. These findings were confirmed by quantitative XRF and ion microprobe analyses of a subsample of Kanjera fossils. The T. oswaldi and hominid fossils had trace element concentrations suggestive of K2 and BCS provenances, respectively. These findings provide a framework for the qualitative XRF provenancing of other surface collected fossils from the locality.