Final answer:
The peacock's large and colorful tail serves as an example of the handicap principle, indicating that despite the survival costs, only the fittest males display such traits, helping peahens choose good genetic partners.
Step-by-step explanation:
A peacock's colorful tail that is used to attract mates but also makes it more visible to predators is an example of the handicap principle. This principle suggests that the tail acts as an honest signal of the male's quality, with the idea being that only the most fit males can afford the survival cost of having such extravagant tails.
The extravagant tails thus help peahens identify males who have good genes and are likely to produce healthy offspring. Sexual selection can often favor traits that compromise survival in favor of increased reproductive success.