Fig. 1

Odor-guided behavioral responses to four odorants. Row 1: Dose response curves of the base population to four odorants. Preference indexes for (a) 4-ethylguaiacol, (b) 4-methylphenol, (c) methyl hexanoate, and (d) ethyl acetate are shown. Gray bars indicate the concentration used in the artificial selection experiments. Data shown are means ± SE. N = 20. Row 2: Phenotypic response to artificial selection for odor-guided behavioral responses to (e) 4-ethylguaiacol, (f) 4-methylphenol, (g) methyl hexanoate, and (h) ethyl acetate. Mean preference index at each generation for the three replicate high selected lines (gray filled dots) and three low selected lines (white filled dots) are shown. N = 6. Row 3: Symmetrical response to selection for (i) 4-ethylguaiacol, (j) 4-methylphenol, (k) methyl hexanoate, and (l) ethyl acetate. Data shown are means ± SE. Letters indicate P < 0.05 using Tukey’s post hoc test. N = 20