Courses/Biol 354
![[D07_Amudsen_and_Forsgren.pdf]] Female ornamentation traditionally seen as a genetic byproduct of pretty males — challenges classic [[sexual selection]] theory (Bateman's principle, good-genes hypothesis) Two-spotted Goby male: iridescent-blue spots and fin patterns. use lateral displays, and lead displays female: during breeding season: conspicuous yellow-orange belly. Carotenoid-based, derived from pigmented eggs visible through skin and orange-red pigment spots in abdominal skin bend bodies towards males showing colorful bellies [[sexual selection|OSR]] shifts throughout season begins male biased but becomes strongly female-biased late in season. Experiment males presented with two females of similar length but differing in natural belly coloration to control influence of roundness/fecundity (colorful=rounder), manipulated color of females with similar length and roundness
Quantitative Results of Male Preference
| Metric | Experiment 1 (Natural) | Experiment 2 (Manipulated) |
|---|---|---|
| Association Time | Males associated ~2x more with colorful females. | Males associated ~2x more with colorful females. |
| Courtship Displays | ~5x higher display rate toward colorful females. | ~5x higher display rate toward colorful females. |
| Statistical Significance | 13 of 15 males preferred colorful females. | 14 of 16 males preferred colorful females. |
| Female behavior was not a factor | ||
| Males die quick after mating, or caring for kids so busy |
More females available late in season