Final answer:
Peacocks use their extravagant tail feathers to attract mates, illustrating the handicap principle, where a significant but burdensome trait signals quality to potential partners. This behavior conflict with simple natural selection, which would decrease such traits if they were only detrimental.
Step-by-step explanation:
Peacocks are known for their beautiful tail feathers, which play a significant role in mating rituals. The display of the feathers is tied to a concept known as the handicap principle, which suggests that male peacocks with larger and more extravagant tails may be seen by females as more fit, despite the increase in predation risk these tails entail. This is because maintaining such a tail requires energy and eluding predators is more challenging, indicating that the male is strong enough to bear this 'handicap.' While the tail is a liability in terms of survival, it acts as an honest signal of quality to potential mates. In contrast, if long extravagant tails were purely disadvantageous, natural selection would trend towards reducing the average tail length over time.
In the animal kingdom, different species use various methods to attract mates. For instance, birds may use unique calls or build structures like bowers, while others, such as the peacock and the Australian lyrebird, utilize their elaborate tails. Feather morphology is crucial for many bird activities, from flight to thermal insulation to communicative displays.