Fig. 2

Reconstructions of Holocene northern Africa. a Palaeoclimate reconstructions³ showing the existence of wet conditions (thick solid lines), semi-arid conditions (thin solid) or arid conditions (dashed). The individual reconstructions are colored by region: Central Sahara (Blue), Eastern Sahara (Red), the Atlas & Hoggar Mountains (Orange). The records discussed in the text are Lake Yoa¹⁷ (green) and marine cores^13,14 (black), whilst records outside of the population regions are coloured gray. The records shown in order of their wet/dry transition, and the total number of wet/dry transitions is shown for each 500 year period. b Probability density of dated archaeological finds for the three regions in northern Africa, which can be used to infer the relative populations²²