Davey F. Wright, Paleontologist

Davey examining a fossilized coral reef from the Pleistocene of San Salvador Island, Bahamas.
I am a paleontologist and macroevolutionary biologist interested in advancing methods to reconstruct evolutionary “family trees” (= phylogenies) containing fossil species and how we can use evolutionary trees to answer questions about large-scale evolutionary patterns and processes. For example, when combined with mathematical models of evolution, phylogenies play a critical role in determining how fast species evolve in nature and why some lineages rapidly multiply into ecologically diverse descendants, whereas others persist in stasis or go extinct.

My taxonomic specialty is the Echinodermata (starfish, sea urchins, and kin), especially the Crinoidea (sea lilies and feather stars), which have a spectacular fossil record spanning nearly a half-billion years. Because echinoderm skeletons are highly complex and commonly preserve ecologic features as fossils (such as feeding structures), they are an ideal group for studying trait evolution and diversification at large scales over geologic time. My research sometimes dabbles with taxonomic databases (such as the Paleobiology Database) and other published sources, but I most frequently gather data my own data from first-hand observations of fossil specimens. The majority of my “fieldwork” involves dredging museum collections for exceptionally preserved specimens, but I also have a passion for paleontology in the field and am always looking for new ways to involve field-based data into my research.

Diversity history of Ordovician through early Silurian crinoids. The Middle to Late Ordovician rise in diversity shows the Great Ordovician Biodiversification Event (GOBE) as expressed in the crinoid fossil record; whereas the subsequent drop in diversity is related to the Late Ordovician mass extinctions. The dotted, vertical line represents the Ordovician–Silurian boundary. Geologic time is represented in million-year units (Ma). (Figure from Wright and Toom, in press)

I am presently involved in a number of different projects, including: new approaches to estimate fossil phylogenies that attempt to account for the incompleteness of the fossil record, ways to statistically test speciation models and ancestor–descendant relationships, and documenting global patterns of biodiversification during key intervals of Earth history. A recent project of mine has focused on disentangling the relationship between rates of evolutionary change and the accumulation of morphological variation within lineages. One might expect that when the rate of morphological evolution increases, you would have an associated increase in the overall diversity of body plans. However, results from my work suggest that elevated rates of evolution are often decoupled with changes in morphological variation. In fact, elevated rates may frequently involve multiple, independent radiations of distantly related species driven toward a pre-existing adaptive optimum by environmental change. Furthermore, major global change events throughout Earth history have acted to create, eliminate, or ‘reset’ ecological optima on the adaptive landscape upon which lineages evolve, which further complicates associations between rates of evolution and the diversity of anatomical forms. In addition to these broader issues, my phylogenetic research has also resulted in major taxonomic revisions of fossil and living crinoids.

Results from a Bayesian “tip-dating” analysis of early to middle Paleozoic crinoids depicting the evolutionary tree with the highest probability, which represents one of many possible hypotheses of relationships. Posterior probabilities are expressed in percent; blue bars represent the range of fossil age estimates; and black bars represent maximum possible stratigraphic durations. (Figure from Wright, 2017)

Being a scientist is fun! When I’m not measuring fossils, coding their anatomical traits, or describing new species, I’m most likely writing R code or conducting some kind of computer-based analysis of paleontological data. Some days I teach or engage in public outreach; other days I brush up on probability theory or new computational methods. Sometimes I daydream about crinoids. One of the best parts of being a scientist is that you get to use your creativity to satiate your intellectual curiosity.

Davey collecting ~350 million-year-old fossil echinoderms in the Brooks Range of Arctic Alaska
As a postdoctoral researcher I’m not sure if I’m qualified to give career advice, but I can at least provide some thoughts about my own experiences. During grad school, I was never able to relate to blog posts and comics on social media that promulgate the stereotype of unhappy, disgruntled graduate students. I am not claiming the path to erudition doesn’t have its share of ups and downs, nor wish to dismiss or downplay the difficulties experienced by others. I would just say that my experience was the exact opposite of the one caricatured by PhD Comics. For me, graduate school was filled with delightful opportunities that would have otherwise been unavailable had I chosen another career path, such learning to program or getting to travel the world. When I first became interested in paleontology, I never expected I would also get to learn so many cool things about geology, molecular evolution, statistics, or computer science. In many ways, the time I spent as a student were some of the best of my life. Nothing can take that away. Enjoy life, keep learning, and stay positive.

To learn more about Davey’s work click through to his website here or follow him on twitter here.

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