 The IPBES definition illustrates the trend to include many other biotic/ecological aspects in the definition. Popular encyclopedia entries on “biodiversity” and major reviews illustrate how this trend has contributed to definitional chaos. In the Encyclopedia of Biodiversity, Swingland argues “An unequivocal, precise, and generally accepted definition of biodiversity does not exist”. in the Routledge Handbook of the Philosophy of Biodiversity, nearly every chapter discusses the “biodiversity” definition problem. The SEP entry supplement  biodiversity preservation under environmental ethics  laments “A persistent complication is that there continues to be no single agreed measure of biodiversity”.