Dale L. Forrister

I'm an evolutionary biologist and chemical ecologist based at the University of Texas at Austin, where I’m a Stengl-Wyer Postdoctoral Scholar.

Read about my fellowship and my journey to UT Austin here.

Explore this site to learn more about my research, publications, and teaching.

Exploring the chemistry of life in tropical forests

My research aims to understand how plant secondary metabolism shapes ecological interactions and biodiversity in tropical forests and across regional to global gradients.

Ecometabolomics and the Phytochemical Landscape

How does phytochemical diversity evolve?

Functional-Metabolomics (HTS + MS)

Ecometabolomics and the Phytochemical Landscape

Ecometabolomics pipeline overview (Fig. 1) — **Fig. 1.** Quantifying the phytochemical landscape using forest dynamics plots and ecometabolomics.

Plants are nature’s chemical factories, drawing 120–160 gigatons of CO₂ annually from the atmosphere and converting it into the world’s forests and grasslands. Beyond building ~80% of global biomass, plants generate over a million specialized metabolites that shape survival, evolution, and species interactions. Life navigates this dynamic phytochemical landscape, where chemical diversity links trophic interactions with nutrient dynamics.

My work uses untargeted mass spectrometry, high-performance computing, machine learning, and modern metabolomics annotation pipelines to quantify chemical variation across spatial and temporal scales (Fig. 1). Together, this ecometabolomics framework brings the phytochemical landscape into focus (Fig. 2).

Scales of chemical variation from individuals to clades (Fig. 2) — **Fig. 2.** Studies quantifying chemical variation across increasing spatial and temporal scales. Adapted from Endara, Forrister & Coley (2023). *Annu. Rev. Ecol. Evol. Syst.* 54:107–27.

Relevant papers

Endara, M.J., Soule, A.J., Forrister, D.L., Dexter, K.G., Pennington, R.T., Nicholls, J.A., et al. (2022). The role of plant secondary metabolites in shaping regional and local plant community assembly. J. Ecol. 110: 34–45.
Forrister, D.L., Endara, M.J., Younkin, G.C., Coley, P.D. & Kursar, T.A. (2019). Herbivores as drivers of negative density dependence in tropical forest saplings. Science 363: 1213–1216.
Schneider, G.F., Coley, P.D., Younkin, G.C., Forrister, D.L., Mills, A.G. & Kursar, T.A. (2019). Phenolics lie at the centre of functional versatility in responses of two phytochemically diverse tropical trees to canopy thinning. J. Exp. Bot. 70: 5853–5864.
Endara, M.J., Coley, P.D., Wiggins, N.L., Forrister, D.L., Younkin, G.C., Nicholls, J.A., et al. (2018). Chemocoding as an identification tool where morphological- and DNA-based methods fall short: Inga as a case study. New Phytol. 218: 847–858.
Forrister, D.L., Tarco, S.L., Donoso, D.A., Garwood, N.C., Valencia, R., Coley, P.D. & Endara, M.-J. (unpub.). Leafing phenology and insect seasonality in an ever-wet tropical forest. Doctoral dissertation, University of Utah.
Wiggins, N.L., Forrister, D.L., Endara, M.J., Coley, P.D. & Kursar, T.A. (2016). Quantitative and qualitative shifts in defensive metabolites define chemical defense investment during leaf development in Inga. Ecol. Evol. 6: 478–492.

All publications

How does phytochemical diversity evolve?
Inga as a model for defense evolution

The Neotropical tree genus Inga (>300 species) is a powerful model for studying the evolution of chemical defenses. Using metabolomics and phylogenetic comparative methods, we showed that closely related Inga species often have highly divergent chemical profiles, with individual compounds and compound classes showing little-to-no phylogenetic signal.

This pattern supports a model of divergent adaptation, where natural selection from specialist herbivores and pathogens drives coexisting species to evolve distinct defensive chemistries. Rather than gradually elaborating on shared pathways, Inga species maximize phytochemical diversity by producing structurally unrelated metabolites.

Increasing chemical divergence over phylogenetic time — **Fig.** Divergent chemical defenses in *Inga*: coexisting and closely replated species evolve highly divergent metabolomes to avoid shared enemies.

Mechanistically, this diversity likely arises from two processes: (1) “Lego-chemistry” — flexible biosynthetic enzymes assembling novel compounds from shared precursors, and (2) regulatory evolution — changes in gene expression that turn biosynthetic pathways on or off, enabling even sister species to deploy different classes of compounds.

Relevant papers

Forrister, D.L., Endara, M.J., Soule, A.J., Younkin, G.C., Mills, A.G., Lokvam, J., Dexter, K.G., Pennington, R.T., Kidner, C.A., Nicholls, J.A., Loiseau, O., Kursar, T.A. & Coley, P.D. (2023). Diversity and divergence: evolution of secondary metabolism in the tropical tree genus Inga. New Phytologist 237: 631–642. doi:10.1111/nph.18554.

All publications

Functional-Metabolomics (HTS + MS)

Coupling untargeted metabolomics with high-throughput screening (HTS) lets us move beyond “lists of features” to ask what plant secondary metabolites actually do. By assaying biological activity in parallel with LC–MS/MS, we can map function onto chemistry, identify bioactive fractions, and link signals back to molecules and pathways.

Current dataset. We’ve screened crude extracts from 125 plant species against 13 fungal pathogens that span ecological niches. This design lets us quantify how toxicity (bioactivity) and investment in defense vary across environmental and phylogenetic gradients, and how community context shapes the selective landscape for plant defenses. (Manuscript in preparation.)

Heatmap of antifungal activity across plant species and pathogens — **Fig.** Example HTS readout: activity heatmap (species × fungal pathogens) highlighting clade- and environment-associated defense syndromes.

Future directions. I am working to scale this approach to functionally annotate the metabolome by: (i) expanding HTS to additional organisms including bacteria, fungal drug targets and insect cell lines, (ii) (iii) using machine learning to relate in vitro effects to metabolite classes and biosynthetic pathways. The goal is a function-aware phytochemical atlas that connects molecules to ecological outcomes.

All publications