Madness in their Method? problematic practices in Palaeobiogeography illustrated by the study of dinosaurs.

Add to your list(s) Download to your calendar using vCal

• Paul Upchurch, Dept. Earth Sciences, UCL
• Wednesday 23 May 2018, 17:00-18:00
• Harker 1, Department of Earth Sciences, Downing Street.

If you have a question about this talk, please contact Andy Buckley.

Palaeo Journal Club : The spatial distributions of organisms are not random, rather they reflect patterns created by the complex interplay between extrinsic abiotic factors and intrinsic biological factors through evolutionary time. As such, the field of Palaeobiogeography forms a key component in our understanding of macroevolutionary patterns and processes. A survey of the extensive literature on dinosaur biogeography reveals a number of problematic issues, including Imprecise definitions of concepts, inappropriate or inadequate analytical approaches, and unresolved concerns about the impact of an incomplete fossil record on putative spatial patterns. Such problems are not unique to the study of dinosaurs but pervade all of palaeobiogeographic research. Even after more than two decades of development of quantitative analytical methods for identifying and testing biogeographic patterns in the fossil record, approximately 90% of studies can be categorised as essentially ‘narrative’ in nature. An example of the problems we encounter is given by the concepts of ‘cosmopolitanism’ and ‘endemism’. Workers frequently claim that a group is cosmopolitan or endemic, and then use this to argue for the operation of biological processes and/or infer palaeogeographic relationships between areas. However, both the logical and evidential nature of these claims can be critiqued. Many problems can be circumvented, or at least ameliorated, through the application of advanced Maximum Likelihood and Bayesian approaches to ancestral area estimation, and network approaches for quantifying biotic ‘connectedness’. Such studies are beginning to reveal important aspects of dinosaur biogeography. For example, there is growing evidence that many groups became widespread across Pangaea prior to the latter’s break up in the Late Jurassic and Cretaceous, and it appears that later endemism on Pangaean fragments is more probably the result of regional extinctions than vicariance. While these new quantitative and probabilistic approaches represent an important step forward, they remain vulnerable to problems caused by uneven sampling of the fossil record and errors in dating divergence times. These latter two issues are likely to form the key areas of advance during the next decade of palaeobiogeographic research.

This talk is part of the Occasional Earth Science Seminars series.

This talk is included in these lists:

• Harker 1, Department of Earth Sciences, Downing Street
• Department of Earth Sciences seminars

Note that ex-directory lists are not shown.