Alverson Lab, University of Arkansas

we study the evolution and diversification of diatoms

Anyone who aspires to be a scientist should be able to pursue that goal. Students and postdocs from all backgrounds have made great contributions to both the spirit and research of our lab. We try to provide a safe space for all people regardless of skin color, gender, sexual orientation, or place of birth. Diverse perspectives lead to better science.

The goal of our research is to identify the ecological and genomic factors driving the evolution and diversification of diatoms. We address our research questions using a blend of phylogenetic, experimental, and comparative genomic approaches. Our research takes us out in the field to make collections from water bodies all over the world. The diatoms that come from these collections are the starting point for most projects. See our recent publications for examples of past and current research.

© Karolina Bryłka

research

Standing on the shoulders of giants

Marine mammals and sea turtles are covered in microbes, including rich communities of diatoms and bacteria. In diatoms, these associations have driven the evolution of new species and novel traits, but the fates of these communities are inextricably linked to their hosts, many of which are threatened by extinction. Through an award from the National Science Foundation, we're working with Matt Ashworth and Tom Frankovich to discover and name new epizoic diatom species. Their phylogenetic relationships will be reconstructed to test hypotheses about the origins, host associations, and genome evolution of epizoic diatoms. Functional relationships between diatoms and their hosts are likely mediated by symbiotic bacteria, so Shady Amin's lab is using metabolomics and metatranscriptomics to reveal the extent to which diatoms rely on host- and bacterial-derived metabolites, which may have driven host specialization of some species.

PHYLOGENY AND DIVERSIFICATION OF DIATOMS

A long-term goal of our research is to reconstruct the phylogeny of diatoms. These projects mine sequence databases, generate large phylogenomic datasets, and use information from the fossil record to ask questions about diatom ecology and evolution. We use these approaches to understand the impacts of life history, habitat, and trait evolution on rates of speciation and extinction through time. Phylogenomic datasets allow us to ask questions about mechanisms of evolutionary change. Like other species-rich lineages across the tree of life, we found that diatoms have experienced numerous rounds of genome duplication. We have also used phylogenomic studies to show how diatoms move back and forth between marine and freshwaters and, in addition, the cascading effects of genome size on diatom physiology and ecology. Our lab is also contributing to the 100 Diatom Genomes Project.

Microbial Adaptation to New and Changing Environments

Although evolutionary biology is a historical science, it also provides a powerful means of looking forward-offering predictions on questions ranging from the spread of human disease to adaptation of species to climate change. Increased atmospheric carbon and global warming are having profound impacts on the world's oceans, including freshening of large parts of the ocean. Although these changes are predicted to have important impacts on the phytoplankton communities in these areas, relatively little data are available to predict how phytoplankton-which produce 40% of the earth's oxygen and form the base of marine food webs-will respond. We are using population genomics and experimental transcriptomics to understand how diatoms have recently adapted to low-salinity habitats, providing insights into how phytoplankton will adjust to a changing ocean.

Evolutionary Transitions Between Marine and Fresh Waters

Habitat transitions are often landmark events in evolution (think colonization of land by plants and animals). Across the tree of life, the diversification of ancestrally marine organisms into freshwaters has led to rapid adaptive change and increased rates of speciation. A primary goal of this research is to understand the adaptations that have allowed diatoms to diversify into freshwater environments, which present numerous obstacles to their marine ancestors. We're using phylogenetics, laboratory experiments, and comparative genomics to understand how diatoms have successfully, and repeatedly, crossed "the salinity barrier".

Most of Earth's biodiversity is invisible to the naked eye. And most of this invisible, microscopic world is composed of single-celled organisms, or microbes. Despite their small size, microbes are the engines that drive Earth's ecosystems. A pinch of soil or a drop of water can contain millions of microbes.

The goal of the myDiatoms project is to introduce students, naturalists, and anyone else interested in biodiversity to diatoms, a lineage of microbes found in virtually all aquatic habitats-from ponds and lakes, trickling books and large rivers, to coastal and open ocean waters.

Recent Publications

2024
Mol Ecol

The divergent responses of salinity generalists to hyposaline stress provide insights into the colonisation of freshwaters by diatoms

Judy KJ, Pinseel E, Downey KM, Lewis JA, Alverson AJ.

2024
J Phycol

The Cretaceous Diatom Database: A tool for investigating early diatom evolution.

Bryłka K, Ashworth MP, Alverson AJ, Conley DJ.

2024
PLoS Biology

Diatom abundance in the polar oceans is predicted by genome size

Roberts WR, Siepielski AM, Alverson AJ.

See all publications

join the lab

We are always interested in recruiting bright, talented, and curious researchers. Undergraduates, graduate students, and postdoctoral fellows excited by our research should directly contact Andy with the information listed below:

If you're interested in joining the lab as a post-doc, e-mail Andy to discuss possible sources of funding.

The Alverson Lab is affiliated with the of Biological Sciences at the University of Arkansas. If you're interested in a graduate student position, please contact Andy to find out if any openings are available before submitting your application.

Exceptional students may be competitive for additional funding opportunities that will supplement the standard graduate stipend. The Department of Biological Sciences is actively recruiting Distinguished Doctoral Fellows (DDF) and Doctoral Academy Fellows (DAF). The DDFs have a salary range of $35,000-$40,000 for a 12-month stipend, and the DAFs have a range of $25,000-$30,000 for a 12-month stipend. Additional information is available here.

We encourage undergraduates to participate in our research program. There are a limited number of these positions available, and we generally only take students who can commit at least two full years to research (freshmen and sophomores are especially encouraged to apply). Interested students should submit a list of current and planned course work along with a 1-2 paragraph statement about why you want to work in our lab.

contact information

Location
University of Arkansas
850 W Dickson St
SCEN 601
Fayetteville, AR 72701-1201

Phone & Email
Office Ph: (479) 575-7975
Lab Ph: (479) 575-4886
aja@uark.edu

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Alverson Laboratory
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