Paleoecological changes at Lake Cuitzeo were not consistent with an extraterrestrial impact

Abstract

Israde-Alcantara et al. (1) reported evidence for the Younger Dryas (YD) Impact Hypothesis (YDIH), which proposes that an extraterrestrial impact triggered the YD (2). Although most YDIH research has focused on the impact event itself, YDIH proponents, as in this article, have argued that the ecological consequences included “widespread biomass burning, and contributed to the extinction of Late Pleistocene megafauna and to major declines in human populations.” To fully test the YDIH, the authors must evaluate evidence and mechanisms for the ecological consequences of an impact. We believe there are flaws in both the interpretation of the paleoecological evidence reviewed by Israde-Alcantara et al. and in its application in testing the YDIH.