Discussion PP

The results for experiment 2 were as expected, and strongly support the hypothesis. In the experiment there were 5 various levels of predation tested. All the data show that as predation increases, spot brightness will decrease over time. This is because the guppies with elaborate colors are more apt to attract predators, thus high spot brightness results in a lower fitness. For the first four levels of predation, the spot brightness still increased. However, the net increase became smaller as predation increased. Finally, with enough predators present, the spot brightness decreased. This is likely because the effects of predation on fitness were stronger than those of sexual selection. Without predation, the data show that spot brightness should increase
substantially over time, due to sexual selection. Therefore, the guppies unknowingly play a fitness balancing game between higher predation and more potential mates.