Biodiversity Dynamics Trough Time and Across Space

My research integrates the modern and fossil record of animal life to build a mechanistic understanding of the production and maintenance of biodiversity. Themes of the recent work that I have contributed to include extinction risk, biogeographic dynamics, biological invasions, biomechanics, and the stability of biological systematics.

Extinction Risk

With David Jablonski and Jim Valentine

Understanding what leads to the demise of biological lineages has become increasingly important in light of the environmental change underway on Earth’s surface today. For the most part, studies of extinction risk have focused on the factors that promote or inhibit the loss of lineages. Here, we extend the study of extinction risk to include two additional components of biodiversity: ecological function and morphology. When considered together, each component of biodiversity reveals new features of the extinction selectivity and the drivers that mediated diversity loss.
Neotrigonia margaritacea

Neotrigonia margaritacea

Global distribution of marine bivalve species.

Global distribution of marine bivalve species.

Biogeographic Dynamics

With David Jablonski

The most famous diversity gradient today–the latitudinal diversity gradient–demonstrates an impressive 50-90% loss in taxonomic diversity from the tropics to the poles in marine bivalves, a model system for macroevolution and macroecology. Range size evolution and extinction appear to have played their part in shaping this current diversity gradient, but physiology and functional ecology may underlie some of the finer-scale variation between biogeographic provinces. Here, we use the functional ecology and body size of species that compose regional faunas to tease apart the sources of diversity differences between coastlines of similar climatic conditions.

biv3d — CT Scanning Marine Bivalvia

With Katie Collins, Kaustuv Roy, Rüdiger Bieler, and David Jablonski

Perhaps an ambitious effort to CT scan every living marine bivalve species that occurs along the continental shelf (depths < 200m), but one that currently stands a ~1200 species and counting (of ~6000 total). These 3D models of the bivalve shell are giving us unprecedented access to the variation in bivalve form and its correlates with ecological function and proxies for the trade-offs in shell construction (e.g., thickness vs. spininess).
CT scans of bivalve shells from the Florida Keys

CT scans of bivalve shells from the Florida Keys

Expected discovery of new marine bivalve species along the continental shelf within 20 years (Edie, Smits, and Jablonski, 2017).

Expected discovery of new marine bivalve species along the continental shelf within 20 years (Edie, Smits, and Jablonski, 2017).

The Effects of Taxonomic Effort on Macroecological Patterns

With David Jablonski, and Peter Smits

While we can’t give an estimate of how many bivalve species escape description, we can still estimate the relative impact that continued species description has on macroecological patterns. In particular, we are looking to emphasize that this description bias carries a strong spatial and phylogenetic weight – two common variables used in macroecological studies. Our first study (Edie, Smits, and Jablonski, 2017) develops an approach to estimating the trends in description rate and their implications for taxonomic saturation. For the next iteration of the model, we plan to incorporate biological characteristics of species to inform our estimates of taxonomic saturation.

The Nature of Marine Bivalve Invasions

With Nicole Bitler and David Jablonski

International shipping and, at first, lax ballast regulation, led to the many different bivalve invasions. This unintentional natural experiment gives us the chance to characterize the ecological nature of these invasions and to extract predictions for the plasticity of bivalve ranges.

Copyright © 2017 Stewart Edie