Figure 1.

(a) Locations of Astatotilapia calliptera populations in Malawi studied. For coordinates see Table 1. (b) Ordination of genetic structure among individuals from seven of the studied populations, based on seven microsatellite loci (Table 2). (c) Principal Component Analysis of environmental similarity of source locations, showing Lake Malawi populations (upper right) and peripheral habitat populations (lower left). Labeled lines indicate associations between the labeled variable and the axis of variation. Temp–Max (maximum monthly temperature), Temp–Min (minimum monthly temperature), Temp–Mean (average monthly temperature), Temp‐C (temperature constancy), Temp‐P (temperature predictability), Temp‐M (temperature contingency), Prep–Max (maximum monthly rainfall), Prep–Min (minimum monthly rainfall), Prep–Mean (average monthly rainfall), Prep‐C (rainfall constancy), Prep‐P (rainfall predictability), Prep‐M (rainfall contingency), flow (presence or absence), deep water (close <1 km or distant >1 km)