The problem with this graph is that before 500 years ago, extinction rates are approximated from studying fossils, which is a notoriously unreliable method of measuring extinction rates. As explained in the textbookBiodiversity and Environmental Philosophy, the “benchmark for assessing the severity of...
H., and J. Botha-Brink. 2014. Anatomy of a mass extinction: sedimentological and taphonomic evidence for drought-induced die-offs at the Permo-Triassic boundary in the main Karoo Basin, South Africa. Palaeogeography, Palaeoclima- tology, Palaeoecology 396:99-118....