Darwin And Giraffe Differences

Giraffes (Giraffa camelopardalis) are the world’s tallest living mammals. Some giraffes are nearly twenty feet tall with necks that are six feet long. The mystery of how the giraffe developed its incredibly long legs and neck is a key argument in the theory of natural selection. The giraffe has also developed an interesting cardiovascular system to accommodate for this adaptation. The heart of a giraffe can maintain a blood pressure 2.5 times greater than humans. There are also hypotheses that the giraffe developed its long neck as a mechanism of sexual selection. Other hypotheses suggest that the giraffe developed its long neck as a feeding advantage to reduce competition amongst other species. Scientists have found genomic evidence to explain
Lamarck hypothesized that the long neck of a giraffe was an acquired element. He speculated that a giraffe’s neck elongating due to constantly stretching its neck to eat the highest crops available, and this trait was also passed to its progeny. Darwin hypothesized that neck elongation was just a herited trait through natural selection. He believed that the giraffe that were most adept to survive were those that could feed on the highest crops available, especially in scenarios when vegetation was in short supply and there would be competition with other short neck herbivores. So, competition for food led to neck
The giraffe has a thermoregulatory advantage because it is tall and presents a narrow shape to the sun. “For this to be evidence of an evolutionary mechanism, the neck should be a good thermal regulator, be free of fur, and have a skin with a good blood supply” (Williams). Since this is not the case, this does not support this mechanism. The giraffe has a special epidermal pattern of dark and light patches and this aids to improve thermoregulation as well, unfortunately it does not provide selection for neck elongation or differential stature. Giraffes have increased lateral size than height that supports