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Fossilized birth-death process

April Wright
Southeastern Louisiana University

The fossilized birth-death process: An overview

April Wright
April Wright

The fossilized birth-death (FBD) process provides a model for inference of phylogeny, divergence times, and other macroevolutionary parameters. The model is typically used as one component in a hierarchical Bayesian model. The other two components are the mode of character (molecular, morphological, or protein) evolution and the clock model. Since its original publication, extensions to the FBD to incorporate additional information, such as biogeographic range and species occurrence counts, have been published. In this talk, I will provide an overview of the fossilized birth-death model. Despite the mathematical extensibility and elegance of the model, it can be difficult for researchers to know how to choose reasonable priors for model parameters. I will also discuss my work using common paleobiological tools to establish reasonable priors on parameters such as speciation, extinction, and fossil sampling. Finally, I will present some practical considerations for model evaluation and exploration of results.

Rachel Warnock

The fossilized birth-death process in paleobiology: Comparison to quantitative palaeontological approaches

The fossilised birth-death (FBD) process provides a modelling framework that explicitly combines the diversification and fossil sampling processes. To date, the model has largely been applied to infer dated phylogenies, based on the analysis of phylogenetic (morphological or molecular) character data. The model can, however, be used to infer key macroevolutionary parameters (origination, extinction and fossil recovery rates), even in the total absence of phylogenetic character data. Here, I will discuss my work into the application of the FBD model to recover metrics commonly used in quantitative paleobiology (origination, extinction, species richness) based on analyses of stratigraphic ranges or fossil occurrence data. The FBD model provides a mechanistic and flexible framework that has several key advantages compared to alternative methods, creating many opportunities for process-based inference in paleobiology.

Joëlle Barido-Sottani
Iowa State University

The fossilized birth-death process in practice: applications and challenges

The fossilized birth-death (FBD) process provides an integrated model for phylogenetic inference by combining the data from fossil samples with extant species into a unified evolutionary process. It has been used for many empirical studies, including total-evidence analyses which use morphological character data in addition to molecular sequences to infer the position of fossils in the phylogeny. However, many questions remain about how to best conduct FBD analyses in practice. User choices on how to model features of the fossil record such as fossil age uncertainty, trait-driven variations in fossil sampling rates, and many others, can have strong and unexpected impacts on inference accuracy. In this talk, I will present my current work exploring the behavior of the FBD process in realistic analyses, demonstrating both the possibilities and the practical challenges associated with integrating fossils into FBD phylogenetic analyses.