How does natural selection explain giraffes’ long necks differently from Lamarckism?

The theory of Lamarckism, proposed by Jean-Baptiste Lamarck, incorrectly suggested that individual giraffes could stretch their necks to reach higher foliage and that these physical changes, acquired during an animal's lifetime, were then passed on to their offspring. As a scientific hypothesis, Lamarckism has been abandoned, as it relies on the inheritance of acquired characteristics, which is not supported by modern genetics.12

In contrast, natural selection explains the evolution of the giraffe’s long neck through the survival and reproduction of individuals with advantageous traits. In ancestral populations, giraffes born with naturally longer necks had a survival advantage, as they could reach food sources unavailable to others. These individuals were more likely to survive and reproduce, thereby passing the genetic basis for longer necks to subsequent generations. Additionally, some scientists propose that sexual selection also played a role, as longer necks provide an advantage in "necking" contests between males to establish dominance and mating rights.1