Pleistocene to Holocene extinction dynamics of Northern Eurasian megafauna, in relation to human activity and environmental change

Lead Research Organisation: University College London
Department Name: Genetics Evolution and Environment

Abstract

We live in a zoologically impoverished world from which many of the largest and most spectacular land animals (called 'megafauna'), e.g. mammoths and sabre tooth cats, have disappeared in the last 40-50 thousand years, at the end of the last ice age and into the postglacial period. The cause or causes of these extinctions remain unresolved. The main contenders are: hunting by modern humans with stone age technologies / known as 'overkill', environmental changes, and a combination of the two. This issue has important implications for the likely impact of humans and/or global warming on the animals of today. Crucial to solving the mystery is accurate information on when and where each megafaunal species became extinct, and what changes in distribution and population size preceded extinctions. Fortunately for Europe and northern Asia, most extinctions occurred within the last 25,000 years, well within the range of radiocarbon dating. We will test ideas that megafaunal distributions expanded and shrank dramatically with environmental changes, leading to reduced and fragmented populations before final extinction. We will also explore how the response of each species differed according to its ecology. However, not all megafaunal range shifts and extinctions can be attributed to changes in the environment, and there is the intriguing new hypothesis that where human populations were densest, this prevented colonization by megafauna. We will obtain some 200 radiocarbon dates (Oxford laboratory) from northern Eurasia made directly on remains of extinct megafauna (woolly mammoth, woolly rhinoceros, giant deer, cave bear) together with two that only survive in other regions (spotted hyaena, lion). Direct dating is more reliable than dates made on associated materials. Any unexpected or outstanding dates will be checked independently by another radiocarbon laboratory (Kiel, Germany). We will target regions where there is currently a critical lack of information, and also species with few dates. Recent work has demonstrated unexpected survival of woolly mammoth, and giant deer (our work) in limited areas, well beyond the end of the ice age (i.e. later than 12,000 years ago). We will pursue other possible late occurrences, with important implications for understanding the processes of final extinction, since climatic fluctuations were generally less extreme after the end of the ice age. In this way we will construct a much more complete picture of megafaunal distributional changes and final extinctions through the last 40,000 years over a very large area. Taking advantage of recent advances (including new, very large datasets) in both stone age archaeology and the history of vegetation from Europe and northern Asia, we will take a fresh approach. From detailed records of human presence at archaeological sites, dated by radiocarbon, we will construct time-sliced maps and time charts tracing the spread and relative population densities of modern humans from 40,000 years ago, onwards. Similarly, from the record of fossil pollen preserved in the sediments of lakes and bogs (European Pollen Database) we will construct time-sliced maps and charts tracking changes in the composition of vegetation. These uniquely detailed records will then be compared with our maps and charts for megafaunal history to look for correlations between events, and thus test the various explanations for the cause or causes of extinctions. We will also look at the histories of several ice age large mammals that did not become extinct in northern Eurasia, e.g. red deer, reindeer, and horse, comparing them with the extinct species to see if ecological, anatomical or other differences were critical for survival, or extinction. We will reconstruct the ecologies of the extinct species from dental and other anatomical information, and from data on vegetation and climate, where megafaunal remains have been found reliably associated with other fossil material.

Publications

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Related Projects

Project Reference Relationship Related To Start End Award Value
NE/D003105/1 01/03/2006 30/06/2007 £457,185
NE/D003105/2 Transfer NE/D003105/1 01/07/2007 28/02/2009 £226,928
 
Description Megafaunal extinctions in northern Eurasia (excluding Mediterranean islands) since the Last Interglacial claimed about 37% of species with body weights above 44 kg. We reviewed the dating evidence for the timings of these extinctions, which were staggered over tens of millennia. Moreover, individual species disappeared at different times in different geographical areas. For example, cave bear probably disappeared ca. 30.5-28.5 ka, at approximately the onset of GS-3 (beginning of 'LGM'), whereas cave lion survived until the Lateglacial ca 14 ka. Others survived into the Holocene: woolly mammoth until ca 10.7 ka in the New Siberian Islands and ca 4 ka on Wrangel Island, giant deer to at least 7.7 ka in western
Siberia and European Russia. It is evident that climatic and vegetational changes had major impacts on species' ranges, and moreover the contrasting chronologies and geographical range contractions are consistent with environmental drivers relating to their differing ecologies. However, the possible role of humans in this process has still to be satisfactorily explored.

We have now published detailed reviews of the radiocarbon record and extinction chronology of woolly rhinoceros, giant deer, cave lion, spotted hyaena and cave bear and assessed them in terms of climatic and vegetational drivers of extinction.
Exploitation Route Climate models and vegetation maps have been used by others interested in last-glacial climates and vegetation. Faunal datelists are being used in species distribution modelling by others.
Sectors Education,Environment,Culture, Heritage, Museums and Collections

URL http://www.nhm.ac.uk/research-curation/earth-sciences/fossil-vertebrates/fossil-vertebrate-research/quaternary-mammals/large-mammal-extinction/index.html
 
Description Quaternary Extinctions Conference 2012 
Form Of Engagement Activity Scientific meeting (conference/symposium etc.)
Part Of Official Scheme? Yes
Type Of Presentation paper presentation
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Conference at Natural History Museum 19 Sept 2012: 'Extinction: The Quaternary Perspective'

One-day meeting bringing together resdearchers and conservation policymakers to showcase the results of the NERC project and those of other researchers in the field, and to build collaborations, especially across the palaeontology-neontology divide.
Year(s) Of Engagement Activity 2012