


Macroevolutionary patterns and processes

Ameura_sp-KUMIP146437 Photo

Curator Bruce S. Lieberman studies the patterns and processes of macroevolution.  His research focuses on the role climate change and abiotic factors play in driving evolution and extinction, the nature of evolutionary radiations, how and why rates of evolution vary through time, the dynamics of mass extinctions, phylogenetics, and biogeography.  Work in his lab has also pioneered the application of Geographic Information Systems (GIS) and Ecological Niche Modeling (ENM) to the study of the fossil record, emphasizing biogeographic and evolutionary patterns in deep time.  Various projects in this area include work with former students and post-docs Erin Saupe, Corinne Myers, Alycia Stigall, and Jonathan Hendricks documenting:


How species niches are conserved over millions of years and the dire consequences our marine biota faces due to changing climate in the near future


The overwhelming role that abiotic factors play in determining long term species survival as opposed to competition

The role that invasive species played in mediating the Late Devonian biodiversity crisis

and the paleobiogeography of the distinctive creatures found in the Burgess Shale

Large-scale Patterns in the History of Life

As part of Lieberman's research interests in macroevolution, and working with Adrian Melott, he has helped demonstrate that there are large scale cycles in the fossil record of biodiversity, origination, and extinction operating on the order of ten’s of millions of year click here to read the article describing this research. 

They have also identified how volatility is a key trait uniting things as diverse as fossil species, stock prices, and the birth and death of stars in our universe. 

Each of these findings indicates that although the history of life is governed by contingency, this contingent system also shows predictable patterns.  

Paleobiogeography photo


Curator Bruce Lieberman has an interest in paleobiogeographic studies and this has formed an important component of his research.  This research has involved phylogenetic approaches, Geographic Information Systems (GIS) and Ecological Niche Modelling (ENM) to study biogeographic patterns in deep time using the fossil record. 

Phylogenetic Patterns in Trilobites and Macroevolution

Lieberman has used phylogenetic patterns in trilobites to consider several macroevolutionary phenomena.  For instance, he has studied the nature of the Cambrian radiation and rates of evolution during this key time period in the history of life. 













Along with former student Francine Abe he also considered tempo and mode of evolution during what is often termed an adaptive radiation of trilobites during the Devonian.  They determined this radiation was not governed by adaptive factors but instead was driven by the complex geography of the region the trilobites occurred in.  This work helped Lieberman to develop a macroevolutionary view of evolutionary radiations, which showed that adaptive radiations are only one type of radiation, abiotic factors rather than adaptation are more likely to have caused most radiations, and exaptation, species selection, and the Turnover Pulse hypothesis are all phenomena that need to be incorporated into the literature on evolutionary radiations. 



Finally, along with former student Curtis Congreve, he considered the tempo and mode of evolution before, during, and after the end Ordovician mass extinction.    










In collaboration with Melott, Lieberman conducted research investigating the nature of the late Ordovician mass extinction and the extent to which it may have been precipitated by a Gamma Ray Burst. This research is described more fully at