Presentation on theme: "Global Modelling of Megafaunal Extinction Climate and Colonisation: Results from a high resolution analysis Lewis Bartlett 1,2, Andrea Manica 2, Graham."— Presentation transcript:
Global Modelling of Megafaunal Extinction Climate and Colonisation: Results from a high resolution analysis Lewis Bartlett 1,2, Andrea Manica 2, Graham Prescott 2, David Williams 2, Andrew Balmford 2 & Rhys Green 2 1 Environment and Sustainability Institute, University of Exeter; 2 Department of Zoology, University of Cambridge.
Research Premise: A Global Analysis for a Global Phenomenon Need for global, integrative assessment of extinction – builds on work of Prescott et al. 2012 1 Split globe into zones: map extinction, expansion, and climate Compare predictive power of climate and early humans – 80,000 year analysis; 4000 year time steps 1 Prescott et al 2012, Quantitative global analysis of the role of climate and people in explaining late Quaternary megafaunal extinctions. Proc. Natl. Acad. Sci.. 109, 4527–4531
ExtinctSurviving Research Premise: Assembling Global Datasets Size of circle represents taxonomic abundance
Analysis Non-linear models: climate only, human only, and combined - iterate over many re-sampled datasets Predict human impact using arrival and zone area
100 60 20 80 40 0 Early Human Arrival Late Human Arrival Percentage Variation Explained (Nagelkerkes R 2 ) Unique to Humans Unique to Climate Shared Explanatory Power: Results: Overall Global Model Performance
logit(prob.extinction)= a*(1+b/LogArea)*T.Human*exp(c*(1+d/LogArea)*T.Human) Predicting Human Effect where T.Human is time since human arrival Function based on the Ricker Model for population density
Your consent to our cookies if you continue to use this website.