Figure 7.

von Humboldt's nightmare: Only the core areas of biomes familiar to us during the Holocene (A) would have remained stable during the ice age (B) when millennial and sub‐millennial climate changes generated widespread ‘weed zones’ in which plant communities may never have had time to equilibrate with climate. We hypothesize that megafaunal species specialized in exploiting the transient, but often highly productive, weedy plant communities flourishing in the grey zones. D‐O is a Dansgaard–Oeschger event. Biome diagram redrawn from Whittaker (1970).