People living in northern Africa just after the end of the last ice age were cooking plants—and the gunk left on their pots proves it. Researchers analyzed 110 pottery fragments (example above; scale bar is 5 centimeters long) unearthed at two sites in what is now southwestern Libya that were occupied, according to previous studies, between 8400 and 10,200 years ago. At the time, portions of that region (now the Sahara Desert) were lush savannas peppered with lakes and crisscrossed by rivers. On 56 of the potsherds, or slightly more than half the fragments, analyses showed a mix of fatty acids in the residues—and, in particular, a high proportion of palmitic acid to stearic acid indicative of plants, the researchers report online today in Nature Plants . The residue on some of the other pots suggested they were used to cook either animal products or a mix of animals and plants, the team notes. Archaeologists had previously found the remains of a variety of plants at these sites—as well as stones used to grind plants and seeds into flour, and even rock art depicting a person picking plants—but the new findings are the first to definitively show that the sites’ occupants actually cooked them. Cooking vegetation not only softened it, but also may have broken down toxic or distasteful compounds, and it may well have set the stage for later domestication of animals in the region, the researchers suggest.