Final answer:
The evolution of long necks in giraffes due to female preference for longer-necked males is an example of sexual selection, where traits enhancing mating success are propagated through generations.
Step-by-step explanation:
The evolution of long necks in giraffes due to female giraffes preferring males with longer necks is an example of sexual selection. In sexual selection, certain traits are favored because they boost mating success rather than survival. Giraffes with longer necks are not only better at securing food resources but are also more attractive to females, leading to more offspring with this trait over time. This aligns with the principle where traits that enhance reproductive success, even if they do not necessarily enhance survival, become more common in the population.
The principle of sexual selection can lead to significant changes in physical characteristics. In giraffes, this has resulted in the development of long necks. Although Lamarck proposed that these traits evolved through use and were then passed on, it is now understood that they arise through genetic inheritance, and long necks became prevalent through a process of selection where females preferentially mate with males possessing longer necks.