David J. Berg


546 Mosler Hall, Hamilton Campus  (513) 785-3246
89 Pearson Hall

Biographical Information

Research in the Aquatic Biodiversity & Conservation (ABC) Laboratory focuses on the evolution and conservation of biodiversity, and the geographic distribution of this diversity across freshwater ecosystems. Our study organisms include amphipods, snails, and other invertebrates inhabiting springs in the Chihuahuan Desert of west Texas and southeastern New Mexico, and freshwater mussels (the most imperiled group of animals in the United States) from throughout North America. The evolutionary forces we study are natural selection, isolation and dispersal among populations, and random changes in genetic diversity and community composition. Springs in the Chihuahuan Desert provide ideal systems for this work because they contain unique assemblages of invertebrates. Stark landscapes, wide-open spaces, and beautiful sunsets are added bonuses for working in this part of the world.

Our work with freshwater mussels has focused on the geographic distribution of genetic diversity within species. We are interested in understanding the mechanisms by which populations of mussels re-inhabited northern rivers following the recessions of Pleistocene glaciers. We also are estimating the degree of gene flow among declining populations when isolation of such populations becomes greater due to habitat fragmentation, climate change, and other anthropogenic causes.

In addition to basic research, we are using molecular genetic tools to answer questions of conservation interest. The National Science Foundation has funded our surveys of desert springs to uncover cryptic biodiversity: new species that are genetically distinct from, but outwardly similar to, known species. Because most of our study organisms are at risk of extinction – largely due to human alteration of habitat – our research is of interest to agencies and organizations that manage endangered species. The U.S. Fish and Wildlife Service, the New Mexico Department of Game and Fish (NMDGF), the World Wildlife Fund, and other agencies and NGOs provide funding for research that informs their efforts at conservation. Our research has provided critical information leading to decisions to list three species of invertebrates under the US Endangered Species Act.

We are now transitioning to using next-generation sequencing tools for investigating the population genomics, evolution, and distribution of diversity in target organisms.This approach genotypes organisms at thousands of loci per individual via Restriction site-Associated DNA Sequencing (so-called RADseq). We are in the process of developing these tools for both freshwater mussels and a variety of desert spring invertebrates. Our research will focus on the use of this information for development of conservation strategies, and on the evolution of traits such as salinity tolerance in desert spring invertebrates.

Courses Taught

Conservation Biology (BIO 467/567)
Invertebrate Zoology (BIO 312)
Fundamentals of Ecology (BIO 209)
Environmental Biology (BIO 121)

Recent Publications

Adams, NE, K Inoue, RA Seidel, BK Lang, and DJ Berg. In review. Isolation drives increased diversification rates in freshwater amphipods. Submitted to Molecular Phylogenetics & Evolution.

Cannizzaro, AG, AD Walters, and DJ Berg. Accepted pending minor revision. A new species of freshwater Gammarus (Amphipoda: Gammaridae) from Terrell County, Texas, with an illustrated key to members of the genus from North America. Journal of Crustacean Biology.

Inoue, K and DJ Berg. 2017. Predicting the effects of climate change on population connectivity and genetic diversity of an imperiled freshwater mussel, Cumberlandia monodonta (Bivalvia: Margaritiferidae), in riverine systems. Global Change Biology 23: 94-107.

Holste, DR, K Inoue, BK Lang, and DJ Berg. 2016. Identification of microsatellite loci and examination of genetic structure for the endangered springsnails Juternia kosteri and Pyrgulopsis roswellensis in the Chihuahuan Desert. Aquatic Conservation: Marine and Freshwater Ecosystems 26: 715-723.

Inoue, K, BK Lang, and DJ Berg. 2015. Past climate change drives current genetic structure of an endangered freshwater mussel species. Molecular Ecology 24: 1910-1926.