Here's why:
* Lamarckism's Key Principle: Lamarck believed that organisms could acquire traits during their lifetime through use and disuse, and then pass those acquired traits on to their offspring.
* The Giraffe Example: In this case, the giraffe's neck stretching due to reaching for food is an acquired trait, not an inherited one. Lamarck would have argued that this acquired trait would be passed down to its offspring, resulting in longer necks in future generations.
Important Note: While Lamarck's theory was influential in its time, it has been largely disproven by modern genetics. We now know that acquired traits are not passed down through inheritance. Instead, evolution occurs through natural selection – traits that are advantageous for survival and reproduction are more likely to be passed on to offspring.
In the case of giraffes, the more likely explanation is that:
* Genetic Variation: There was already genetic variation in neck length within the giraffe population.
* Natural Selection: Giraffes with slightly longer necks had an advantage in reaching higher food sources, giving them better access to nutrition and survival. This led to them being more likely to reproduce and pass on their genes, increasing the frequency of longer necks in the population over time.