Effects of gaps on proxy records and evolutionary history in carbonate platforms: interactive visualizations and teaching tools via R Shiny apps and CarboCAT

The stratigraphic record preserves key information on past climate and evolutionary dynamics in the form of fossils and proxies. However, not all information can be recovered due to gaps in the stratigraphic record. It is challenging to assess (1) how strong the stratigraphic overprint of geohistorical data is (2) how it changes along an onshore-offshore gradient, and (3) how it is linked to external drivers of basin formation such as variation in sea level. Stratigraphic paleobiology has demonstrated how gaps distort reconstructed rates of evolutionary events and positions of stratigraphic markers in a non-random pattern. Yet a systematic evaluation of their effects on information reconstructed from strata is lacking.

We present DarwinCAT and ProxyCAT, two interactive web-based applications that visualize how stratigraphic architectures systematically change the expression of evolutionary history and proxy records. They combine simulations of a carbonate platform generated in CarboCAT with geohistorical records simulated in the R software into a Shiny app. They can be used in any web browser and require no installation or coding knowledge. In addition to simulations of trait evolution and proxy records, users can upload their own proxy data and examine its preservation in different parts of the carbonate platform.

Due to their strong visual component and interactive interface, the apps are an intuitive and easy to use tool for teaching, self study, and science communication. To facilitate their use for teaching, we provide predefined teaching units for undergraduate and graduate students of the geobiosciences. The teaching units allow exploring the preservation of geohistorical records within a stratigraphic framework, as well as hypothesis-driven research.