Fig. 3. The genetic causes of co-culture and monoculture specific evolution.

A E. coli and S. cerevisiae populations from co-cultures were sequenced after 420 (two populations) and 980 generations (E. coli = seven and S. cerevisiae = six populations) and monoculture populations were sequenced after 980 generations (three populations) (Supplementary Data). In E. coli, mutations in five genes were found to be at high frequencies in all populations (A, grey shaded area). B Six independent mutations were found across the co-culture evolved populations in btuB and fhuA and two in glyQ. Population E10 had two mutations in both btuB and fhuA. All three monoculture populations had unique mutations in the dusB/fis operon. C BUL1 was mutated in all sequenced S. cerevisiae populations. Coloured text indicates the species present at generation 980. E. coli and S. cerevisiae (green text), E. coli only (blue text), S. cerevisiae only (orange text). Alphanumeric population codes (e.g., cC6) denote whether the population was evolved in coevolution (C) or monoculture (M) conditions and the position in the 96-well plate. “pm” indicates promoter, “*” indicates early stop or nonsense mutations. “–” indicates that no mutation was discovered in that gene.