Fig. 6
The effect of the initial allele frequencies on alewife morphological evolution. P(A) t=0 was the initial frequency of the allele improving alewives’ growth. P(B) t=0 was the initial frequency of the allele increasing alewives’ gill-raker number. \(\bar {P(A)}\) was the mean frequency of the allele improving alewives’ growth. \(\bar {P(B)}\) was the mean frequency of the allele increasing alewives’ gill-raker number. The intensity of within-trophic competitions was low (eA=0.75). Trophic interaction were strong (eI=0.25). The reduction in alewives’ body size substantially improved the efficiency of their foraging for small prey (eb=0.125). Alewives’ small gill-raker spacing moderately undermined the efficiency of their foraging for large prey (lp=0.5). Allele frequencies were recorded every 1000 years in this figure