Final answer:
According to Delph and colleagues (1996), sexual selection is often stronger for male flowers, driven by the greater variance in their reproductive success, leading to traits that improve their chances of mating.
Step-by-step explanation:
The experiments conducted by Delph and colleagues (1996) indicate that sexual selection is often stronger for male flowers than for female flowers. This is because males tend to have more variance in reproductive success, leading to selective pressures to develop traits that improve mating opportunities. Traits such as size, strength, and ornamental features like colorful plumage in birds can increase a male's chances of securing matings. However, these secondary sexual characteristics sometimes do not enhance, and may even impair, the individual's survival chances, demonstrating the power of sexual selection. An example of this is the peacock's tail, which is attractive to females even though it is impractical for survival. The handicap principle suggests that such costly traits indicate genetic fitness. In some species, there is a sex-role reversal wherein females exhibit these extreme traits due to greater variance in their reproductive success.