Author: Christopher William Dick

We will be welcoming a new post-doc in the lab next term – Greg Stull. Greg, who is finishing his dissertation in the Soltis lab, was awarded an NSF post-doctoral fellowship for “Research Using Biological Collections”. These fellowships are meant to support transformative science that employs biological collections.

The title of Greg’s post-doctoral fellowship is ” Integrating diverse collections data for deep-time distribution modeling in a tropical flowering plant family (Icacinaceae) with an extensive fossil record.”  Stephen Smith and I (Chris Dick) will serve as the sponsoring scientists.

Below is part of the abstract for Greg NSF Fellowship.

Understanding how species have responded to previous instances of climate change is critical for predicting the impact of future climate change on the distribution of biological diversity. Because the fossil record is highly incomplete, additional tools are necessary to reconstruct historical distributions at different points in the past (e.g., when the earth’s climate was considerably warmer during the early Eocene, ca. 50 Ma). Species distribution modeling (SDM) has emerged as a powerful computational tool for modeling the ecological requirements of species, using the wealth of locality/geographic data available for modern species in natural history collections. SDM has been used extensively to predict possible future distributions as shaped by climate change; the application of SDM for reconstructing distributions in deep time, however, has been underexplored, despite its potential for understanding how climate change has shaped the diversity and distribution of organisms through time. The fellowship research will explore and expand methods of using geographic data from modern species, obtained through online repositories of collections data from around the world (e.g., GBIF, iDigBio), to generate species distribution models of extinct species, allowing for the reconstruction of distribution patterns across broad time scales (e.g., the past 65 Ma). This research will use as a model the pantropical plant family Icacinaceae, which has an extensive fossil record, allowing for the validation of the historical projections and, by extension, the methods used to generate them. In particular, this research will investigate the climatic suitability of major land bridges/rafts for the migration of tropical plants throughout the Cenozoic (65 Ma to present). The will constitute one of the first studies to employ SDM across such a broad time scale, using the fossil record to validate the results. This research will therefore serve as an important proof of concept for this approach, and the novel methodological tools generated will advance future research related to biogeography and climate change.

Welcome Greg!

Geogenomics post-doc James Pease (working jointly between the Dick and Smith labs) and colleagues have just published a major paper on the phylogenomics of the tomato lineage, which has its origin in the Andean uplands. Here is the U-M press release, and here is a link to the Plos Biology paper. Using transcriptome data, this paper examines the major sources of adaptive variation in tomatoes, including adaptations associated with climatic and edaphic environments (e.g. heavy metal tolerance). Interestingly, much of the adaptive variation was obtained through introgressive hybridization. This paper is full of data, insights, and is at the leading edge of the integration of transcriptomics, phylogeny and biogeography. Congrats James!

January 19, 2016

I’ve received quite a few comments on an article I wrote regarding Ann Arbor’s plan to cull 100 whitetail deer from its parks and natural areas (I support the cull for ecological reasons). Here is my article published in Bridge Magazine. This was followed by write-up in the UM Record, followed by an article in AnnArbor.com, and an interview with WEMU. To understand the extent of the controversy, simply read through the comments sections. This is a topic with multiple dimensions. I think a clear presentation of the biological impacts of deer overpopulation is an essential part of the discussion.

Na Wei successfully defended her doctoral dissertation (and with flying colors!) on April 14, 2015. Her dissertation, entitled GENE DISPERSAL IN TROPICAL TREES: ECOLOGICAL PROCESSES AND GENETIC CONSEQUENCES involved detailed population genetic studies of four tree species on Barro Colorado Island. Na did extensive genetic marker development, mathematical modeling and grueling fieldwork, with an overall goal of understanding how seed and pollen movement differentially contribute to gene flow (and genetic structure) in tropical trees. Na has already published 4 papers (with a fifth in revision) and has several larger papers in the pipeline. Excellent work Na!

Congratulations go to Jordan for his NSF Doctoral Dissertation Improvement Grant!

Jordan’s project is called “A hypothesis test for cryptic northern refugia in bitternut and shagbark hickory, with implications for migration and adaptation.”

From the EEB news release:

The DDIG will support Jordan’s research into the locations of glacial refugia for temperate tree species from eastern North America. “During the peak of the ice age around 21,500 years ago, glaciers covered much of northern North America and climatic conditions forced temperate forests into refugia along the Gulf of Mexico and southern Atlantic Coast,” Bemmels explained. “Recent research has suggested that there may have been additional cryptic refugia located much farther north, such as in the southern Appalachians and Ozarks, but this idea has been controversial. Determining where tree species survived the ice age is important for understanding how trees have migrated and adapted in response to past climate changes, and will have implications for forestry and conservation biology. Using bitternut and shagbark hickory as a study system, I will combine genetic data from populations across the United States with computer simulations in order to test competing hypotheses about glacial refugia. This will be the first time that a level of statistical support for the presence of cryptic refugia will be determined.

“Understanding migration and adaptation of trees in response to historical climate change will help us manage the forests of today and in a warming world.” He will receive $18,250 over two years.

July 29, 2014 – The CW Dick and SA Smith labs (EEB Department, University of Michigan) are seeking to fill two post-doctoral positions as part of an NSF funded “Geogenomics” project. The goal of the project is to use phylogenetic data from Andean and Amazon plant groups to test hypotheses pertaining (especially) to the uplift history of the Andean region. A computationally-oriented post-doc will primarily analyze published data within an open source tree-of-life framework; an empirically-focused post-doc will perform de novo phylogenetic analyses of select Andean-Amazon plant groups using genomic and transcriptomic tools. There are possibilities for South American field work and interdisciplinary collaborations with geologists, ecological modelers, and paleontologists. If interested please send a statement of interest and CV to cwdick@umich.edu.