Below, you can read about my ongoing research projects.

Photonics of Coral Reef Animals

I apply computational optics to understand how solar energy influences coral reef ecosystems and their breakdown through coral bleaching. Specifically, I research how photosymbiotic animals– corals, bivalve mollusks, and more– harness sunlight with photonic adaptations at the nano-, micro-, and macro-scale. I test evolutionary hypotheses by characterizing these photonic adaptations, combining high performance optical simulations with evolutionary theory and advanced material characterization. My colleagues and I showed that reef-dwelling bivalves called heart cockles have transparent shell windows composed of natural fiber optic cables that screen out harmful UV light through scattering and absorption (see poster). The cockles also use condensing lenses to focus light into a beam. In contrast, some coral species’ photonic adaptations concentrate light on algal symbionts and accelerate bleaching, while corals who lack those light-concentrating adaptations tend to resist bleaching (project in prep.). Last summer, I traveled to Palau with the Palumbi lab and conducted experiments on light stress and light environment in the lab and in the field; stay tuned for more.

City Trees Project

city tree trimming in Durham, NC City trees capture and store carbon dioxide, cool local temperatures, and improve our mental and physical health. Trees are good for humans! But urban forests are also ecosystems that provide habitat for bird and insect communities. Thanks to city tree inventories across the US and the world, we have an unprecedented opportunity to research ecosystem function from the meter-scale to the global-scale. My team and I have assembled a dataset of over 5 million city trees from 63 of the largest cities in the USA, including data on species, exact location, condition, and trunk diameter; you can view and download our data on Dryad. We found that urban forests in the USA tend to group similar tree species together and rely heavily on introduced species, which may decrease resilience and reduce their benefits for people and animals. Wetter, cooler cities had more naturally occurring trees, while drier, hotter communities had more introduced species. Read more about our paper in this eLife digest. Future projects will investigate whether tree diversity relates to bird and insect diversity, and whether tree diversity correlates with socieioeconomic status. As they say, trees grow on money. This project is co-led by Ben Goulet-Scott; photo at right by Ildar Sagdejev (CC-BY-3.0). Click the image to read our paper and learn more!

Super Black Animals (& Bioinspired Solar Tech)

Birds of Paradise have super black color Male birds-of-paradise, perhaps nature’s most ornate and elaborate creatures, evolved ultra-dark super black framing brilliant color. Unlike typical feathers, the feathers of super black plumages have 3-D microstructures on their barbules which multiply scatter, and iteratively absorb, nearly all light. Click the image to learn more!

Peacock spiders have super black color Peacock spiders have evolved ultra-dark black color adjacent to their brilliant color patches. They are a remarkable convergence of form– microlenses, used in nature on everything from plant leaves to moth eyes– and function– ultra black near bright color for color emphasis, akin to their ecological analogues (the Birds-of-Paradise). Click the image to learn more!

Many bird evolved super black color Super black plumages evolved in birds from 15 families, with diverse morphology underpinning the plumages. Several families convergently evolved similar morphologies (e.g., curved, uwpard-branching barbules). Click the image to learn more!

Tanagers have microstructures to enhance pigment Male, but not female, tanager feathers have elaborate microstructures which amplify the saturation of red, orange, and yellow colors. These colors are produced by carotenoid pigments, classically thought to be honest signals of quality. Click the image to learn more!

Biology of Pregnancy

Embryo selection and mate choice Just as females screen potential mates under many metrics, human mothers unconsciously screen embryos for quality. ‘Examinees’ are under intense selection to improve test performance by exaggerating formerly ‘honest’ signals of quality. By the ‘proxy treadmill’, new honest indicators arise while old degraded indicators linger, resulting in trait elaboration. Hormone signals during pregnancy show extreme evolutionary escalation (akin to elaborate mating displays). Click the image to learn more!

Marmosets Primates are model organisms for questions of cooperation and conflict within families,and callitrichines (marmosets, tamarins, and lion tamarins) frequently bear litters of two or more. We compiled a large dataset of nine species of callitrichines (n  = 27,080 individuals) and found two indications of sibling conflict: (i) Singletons have higher survivorship than litter‐born monkeys and outperform their litter‐born peers on two measures of reproductive success, and (ii) offspring born into mixed‐sex litters reproductively outperform those born in all‐male or all‐female litters in some species, suggesting that same‐sex competition may limit fitness outcomes. Click the image to learn more!