Sarah Leventhal

Sarah Leventhal

Postdoctoral fellow, Department of Paleobiology, NMNH. Big fan of modular invertebrates

Publications

The impact of an informal education program on participant attitudes towards science across remote and in-person settings.

Published in Journal of STEM Outreach, 2023

The Girls at the Museum Exploring Science (GAMES) program, run out of the University of Colorado Museum of Natural History for the last 20 years, is a community engagement program that aims to foster a positive attitude towards science in elementary school-aged girls. Since the start of the COVID-19 pandemic, the in-person GAMES program has added remote sessions.

Recommended citation: Leventhal, S., Sullivan, G., Regan, K., and Li, J. The impact of an informal education program on participant attitudes towards science across remote and in-person settings. Journal of STEM Outreach (in press).

Aggregate Trait Evolvability and Macroevolution in Two Sister Species of the Bryozoan Stylopoma

Published in Evolutionary Biology, 2022

Abstract: The study of trait evolution in modular animals is more complicated than that in solitary animals, because a single genotype of a modular colony can express an enormous range of phenotypic variation. Furthermore, traits can occur either at the module level or at the colony level. However, it is unclear how the traits at the colony level evolve. We test whether colony-level aggregate traits, defined as the summary statistics of a phenotypic distribution, can evolve. To quantify this evolutionary potential, we use parent-offspring pairs in two sister species of the bryozoan Stylopoma , grown and bred in a common garden breeding experiment. We find that the medians of phenotypic distributions are evolvable between generations of colonies. We also find that the structure of this evolutionary potential differs between these two species. The ancestral species aligns more closely with the direction of species divergence than the descendent species. This result indicates that aggregate trait evolvability can itself evolve.

Recommended citation: Leventhal, S., Jamison-Todd, S. & Simpson, C. (2022). Aggregate Trait Evolvability and Macroevolution in Two Sister Species of the Bryozoan Stylopoma. Evol Biol. https://link.springer.com/article/10.1007/s11692-022-09588-8

Early proliferation of avicularia in the Cretaceous cheilostome bryozoan Wilbertopora: a diversification event guided by ecological exploration

Published in Bryozoan Studies 2022, 2022

Cheilostome bryozoans are a diverse clade of colonial animals that first appeared during the Jurassic period. For the first 100 Myr of their existence, colonies of cheilostomes were monomorphic, composed entirely of autozooids. Divergent body types, termed avicularia, first appeared in colonies in the early Cretaceous period, in the genus Wilbertopora. Over the course of the Cretaceous, Wilbertopora diversified into 27 species, spanning the early Albian through Maastrichtian stages. In this study, we quantify autozooid and avicularia shape and size to evaluate how the morphological disparity of zooid types in colonies changes over the course of Wilbertopora diversification. We find that taxonomic diversity and morphological disparity are largely decoupled, with disparity outpacing diversity for much of Wilbertopora’s evolutionary history. Increases in disparity are primarily driven by evolution of avicularian morphology, indicating that Wilbertopora’s avicularia may have served an array of purposes in different lineages.

Recommended citation: Leventhal, S.E., Stowe, K., and Simpson, C. Early proliferation of avicularia in the Cretaceous cheilostome bryozoan Wilbertopora: a diversification event guided by ecological exploration. In: M.M. Key, Jr., J.S. Porter, and P.N. Wyse Jackson (eds). Bryozoan Studies 2022. Rotterdam: Balkema (in press).