Using palaeoecology to determine baseline ecological requirements and interaction networks for de‐extinction candidate species

Summary A key rationale for pursuing de‐extinction is the potential to restore lost processes and function to modern ecosystems. However, understanding and providing for the ecological requirements of the candidate species will also play a key role in determining the ultimate success of a de‐extinction. This assessment is challenging for prehistoric extinct species, where empirical studies or observations on their ecology are not available or are incomplete. A healthy, stable and self‐sustaining population of a resurrected species needs to be embedded in an ecological interaction network that consists not only of interactions between a resurrected species and its external environment (e.g. habitat, diet), but also those where the resurrected species is the environment (e.g. microbiota and parasites). Palaeoecology can provide information on all of these interactions for extinct species, and this information can help guide and inform the selection of suitable de‐extinction candidates or traits for resurrection. Ecological interaction network analyses offer a complementary tool to existing frameworks for determining the suitability of de‐extinction candidates, allowing palaeoecological information to be used to identify and quantify the potential implications of removing or adding resurrected species/functions to an ecosystem. Although palaeoecological data and understanding clearly have an important role in informing and modelling the potential ecological functions provided by extinct species, they can only ever provide an incomplete picture and therefore would only complement, rather than replace, observational or experimental data on the resurrected organisms themselves. A lay summary is available for this article.