Abstract next monthly IGBA symposium
Hominin adaptation to environmental challenges in north-west Europe
Speaker: Katherine mac Donald (Leiden University)
Hominins were first present in north-west Europe between 1.0 and 0.74 million years ago (Ma). The earliest occupants of this region were confronted with new environmental challenges, including high seasonality and cold winter temperatures. In addition, after 1 million years ago, this region saw major changes in palaeogeography, fauna and flora. This region provides an excellent context for understanding the hominin niche and how they adapted to these challenging conditions between 1.0 - 0.3 Ma. The earliest occupants may have tracked favourable conditions into this region from refugial areas. According to one hypothesis, they were limited to the warmest interglacial phases and to areas in which temperate climatic conditions prevailed due to proximity to the ocean1. Only after c. 0.5 Ma were hominins able to occupy cooler and more continental conditions, perhaps because of new behavioural adaptations (e.g. fire) or increasing brain size perhaps supporting greater adaptive flexibility. Alternatively, the first tool-using hominins in Europe may have been capable of solving new environmental problems at mid-latitudes c. 1 Ma. These scenarios have contrasting implications for the spatial distribution of archaeological sites; however, it is difficult to disentangle the influence of hominin habitat preference (or even tolerance) from habitat preservation. In addition, refugial areas to the south and east played an important role in the distribution and evolution of hominins in Europe, and are important in order to understand what conditions hominins experienced in their core areas, and hence the role of habitat tracking. This paper will present ongoing work addressing these themes and research questions.
1. Cohen, K.M., MacDonald, K., Joordens, J.C.A., Roebroeks, W. and Gibbard, P., this issue. Earliest occupation of north-western Europe: a coastal perspective. Quaternary International 2011, doi:10.1016/j.quaint.2011.11.003.
High-resolution correlation between fossil hominin and climate records in the Turkana Basin, Kenya: implications for our views on evolution of the genus Homo
Speaker: Jose Joordens (Leiden University)
Josephine C.A. Joordens, Guillaume Dupont-Nivet, Craig. S. Feibel, Mark J. Sier, Jeroen H.J.L. van der Lubbe, Trine Kellberg Nielsen, Monika Knul, Gareth R. Davies, Hubert B. Vonhof.
To interpret hominin fossils in the context of climate cyclicity, Joordens et al (2011) constructed a cyclostratigraphic framework for upper Burgi Member deposits on the Koobi Fora Ridge, Turkana Basin. However, many hominin fossils derive from the nearby Karari Ridge. So far, lack of regional marker beds has prevented correlation between sequences from Koobi Fora and Karari Ridges. This lack of age control precluded using key hominin fossils in evaluation of their environmental and climatic setting, and phylogenetic position. To remedy this, we conducted magneto- and Sr-isotope stratigraphy in two UBU sequences on the Karari Ridge. In each sequence we established the base of the Olduvai chron (~1.95 Ma) and obtained one Sr-isotope cycle representing one precession cycle. This strongly improves age control and allows placement of fossils in the climate framework. We discuss the implications of these results for insights in the evolution and dispersal of the genus Homo.
Joordens, J.C.A., Vonhof, H.B., Feibel, C.S., Lourens, L.J., Dupont-Nivet, G., van der Lubbe, H.J.L, Sier, M.J., Davies, G.R., Kroon, D., 2011. An astronomically-tuned climate framework for hominins in the Turkana Basin. Earth Planet. Sci. Lett. 307 (1-2): 1-8.
