Making eDNA more digestible: a pizza analogy for understanding false negatives and occupancy modeling

Environmental DNA (eDNA) sequencing from water samples has emerged as a promising and cost-effective approach to collect comprehensive freshwater biodiversity data. However, critics might highlight potential shortcomings, such as the possibility of false positives (detection of absent species) and false negatives (failing to detect a species that is present). Misconceptions and misunderstandings may also stem from the complexity of the scientific approach and technical language, with implications for decision-makers and potentially hindering conservation. In the present article, we propose an analogy of eating a pizza to simplify messaging and increase understanding of detection probability within typical eDNA metabarcoding workflows. The pizza represents a site, slices represent water samples, bites represent PCR replicates, toppings represent species and olives represent a low-abundance species. Overall, the pizza analogy provides a novel, lighthearted and memorable way to communicate complex eDNA workflows to a broad spectrum of biological scientists and practitioners.