Senior Marine Scientist
Assistant Professor, Dept. of Biological Sciences, University of Alabama
Ph.D., Evolution & Ecology, The Ohio State University, 2017
Postdoctoral research: American Museum of Natural History, 2018-2020
Postdoctoral research: University of Lausanne, Switzerland, 2020-2021
Research in the Titus Lab uses the iconic mutualisms from tropical coral reefs to understand the evolutionary and ecological processes that generate biodiversity in these tightly linked interactions. We combine field research, systematics, and genomic approaches to understand mutualisms at all levels of biological organization. Our lab is currently focused on three main projects involving sea anemones and the clownfish-sea anemone symbiosis.
- Systematics and Species delimitation of the clownfish-hosting sea anemones: The clownfish-sea anemone symbiosis has been used as a model mutualism for exploring fundamental biological processes. However, the 10 nominally described species of host anemones have only been described morphologically. The presence of cryptic host anemone taxa thus holds the potential to transform our evolutionary understanding of this symbiosis and bear on the interpretation of dozens of studies that span scientific disciplines. Using newly developed bait-capture probes targeting Ultra Conserved Elements we are using range-wide sampling and genomic species delimitation approaches to disentangle the true species-level diversity of the host anemones. This work is currently funded by the National Science Foundation
- Origin of tropical sea anemone diversity: Contrary to the generally observed pattern of hyperdiversity in the tropics, anemone diversity peaks in temperate ecosystems. As a result, tropical species have received a fraction of the scientific attention as temperate ones, with no major efforts in the systematics of tropical anemone diversity since the advent of modern DNA sequencing. Compounding a lack of systematic effort in the tropics, anemones have few diagnostic morphological characters and slowly evolving mitochondrial DNA that is ineffective as a species-level marker. Thus, it is likely that tropical anemone diversity is vastly under-described, and a genomic approach is required to simultaneously delimit species, place them into broader phylogenomic context, and determine what morphological characters are informative at every hierarchical level. Using newly developed bait-capture probes for Class Anthozoa, we are testing whether the tropics are a center of origin, or a center of accumulation, of tropical sea anemone diversity. This project will be the first major phylogenomic reconstruction within the Order Actiniaria and is funded by the National Science Foundation.
- Genomic consequences and convergence in a model marine mutualism: Mutualisms can radically shape the architecture of the genome, trigger adaptive radiations, lead to rapid population expansions, and impact rates of molecular evolution. Using the multiple origins of symbiosis with clownfishes as a research framework, our lab is conducting full genome sequencing of the clownfish-hosting sea anemones to test general evolutionary expectations of mutualism. Specifically, we are testing: 1) whether mutualism with clownfishes has generated similar selective pressure and therefore resulted in convergent genome evolution and architecture among host anemones. 2) The Red King Hypothesis, which states that the balance of mutually exploitative symbioses should lead constituent mutualistic lineages to have slower rates of molecular evolution than their free-living relatives. 3) Whether the mutualistic benefits of hosting clownfishes led to the significant ecological opportunity for host anemones, and thus, signatures of demographic population expansion that coincide with the onset of the symbiosis.