Umberto Lombardo, Manuel Arroyo-Kalin , Hans Huisman, Wenceslau Geraldes Teixeira, Charles R Clement, Carlos Francisco Brazão Vieira Alho, Fernando Almeida, Lucia Helena Cunha Anjos, Christopher Bronk Ramsey, George Brown, Marcondes Costa, Luis Cunha, William M Denevan, Ademir Fontana, Bruno Glaser, Susanna Hecht, Klaus A Jarosch, André Braga Junqueira, Thiago Kater, Thomas W Kuyper, Johannes Lehmann, Helena Pinto Lima, Rodrigo Santana Macedo, Marco Madella, S. Yoshi Maezumi, Francis E Mayle, Doyle McKEY, Claide de Paula Moraes, Gaspar Morcote-Ríos, Eduardo Neves, Francisco Pugliese, Fabiano Pupim, Marco F Raczka, Anne Rapp Py-Daniel, Philip Riris, Leonor Rodrigues, Stéphen Rostain, Morgan Schmidt, Myrtle P Shock, Tobias Sprafke, Eduardo Kazuo Tamanaha, Pablo Vidal-Torrado, Ximena S Villagran, Jennifer Watling, Sadie L Weber

First described over 120 years ago in Brazil, Amazonian Dark Earths (ADEs) are expanses of dark soil that are exceptionally fertile and contain large quantities of archaeological artefacts. The elevated fertility of the dark and often deep A horizon of ADEs is widely regarded as an outcome of pre-Columbian human influence. Controversially, in their recent paper Silva et al.2argue that the higher fertility of ADEs is principally a result of fluvial deposition and pre-Columbian peoples just made use of these locales rather than contributing to their enhancement. Soil formation is inherently complex and often difficult to interpret, requiring a combination of geochemical data, stratigraphy, and dating. Although Silva et al. use this combination of methods to make their case, their study, based on the analysis of a single ADE site and its immediate surroundings, is too limited to distinguish among the possible mechanisms for ADE formation. Silva et al.’s conclusions contradict decades of research by archaeologists, soil scientists, geographers and anthropologists, who agree that ADEs are anthropic soils formed on land surfaces enriched by inputs resulting from pre-Columbian sedentary settlement. To be accepted, and be pertinent at a regional level, Silva et al.’s hypothesis would need to be supported by extremely solid evidence, which we demonstrate is lacking.