Giraffes are fascinating animals that appeared around 16 million years ago and are said to have possibly evolved from antelopes.Over the past decades, several questions regarding their evolution and lifestyle have been raised and led to various theories, debates, and even more questions. For example, are these animals related to long-necked dinosaurs and how did they evolve in such an unusual manner?When the Earth was forming billions of years ago, several organisms evolved from microbes with single cells and eventually further evolved to be the common ancestor to every life form and creature. For over 2 billion years, the process of evolution had given shape to all life forms, even before animals evolved from primal ancestors.The animal this article focuses on is known as the tallest land mammal alive, because of its majestic looks that it owes to its long neck, legs, and impressive stature. Male giraffes can measure up to 18 ft (5.5 m) in height, females are tall but slightly shorter than the male members. The way this fascinating animal has evolved over millions of years or the process of the evolution of this species is still a mystery waiting to be solved. Several scientists, however, have theorized that they were closely related to nematodes or arthropods, based on results of several research and analyses of the genomes and body structures of several tardigrade species. Given that so much of the animal’s past and evolutionary history is still in the dark and a mystery, it made understanding the nature and function of their unusually long necks and legs challenging as well.If you think this article is fun to read, you might also like why horses need shoes or why chinchillas take dust baths here on Kidadl.How long are giraffes necks?Everyone knows giraffes have extraordinarily long necks, making them the tallest mammals on earth, but just how long are they?Their necks can grow up to 7 ft (2.1 m) in length, which can be almost half of their overall height, 18 ft tall (5.5 m)! Like human beings and several other mammals, they also have seven vertebrae present in their necks. Researchers have tested several hypotheses that explain how a giraffe’s long neck helps conveniently regulate its body temperature.Because this animal appears to have a larger and broader surface area compared to barrel-shaped animals like elephants and rhinos, the hypothesis is dragged and used all the time until a different and better explanation seems to fit. Jean Baptiste Lamarck, a French naturalist, suggested that the necks of these animals neck because of their continual striving to reach food without falling prey to any predators.Later, a recent genetic version of this idea supported the fact that biological evolution for better height and reach was the main reason for this strange development, rather than other reasons such as defending themselves from predatory attacks as they only continue living up to 25 years in the wild. Also, the horns present on top of their heads are simply used to push back branches and dead leaves so that they can feed more and better quality food.How are giraffes’ long necks adapted to their lifestyle?The most common idea and explanation for why and how these animals use their necks in their daily lives is that these necks allow giraffes to feed themselves. A giraffe’s long neck is said to be the perfect and optimal adaptation to its natural habitat, but giraffes may not have evolved long necks just to reach tall trees and feed on some nourishing leaves, as most of us believe.Even though this theory put forth by some scientists fits well and is highly persuasive, the idea as a whole fails to explain multiple things, for instance, sexual selection. Over the past few years, several other theories have also become popular and are being studied in depth to understand their nature and lifestyle better.Research to identify genetic changes with a giraffe’s unique traits and qualities was conducted a while ago. Here, scientists compared the gene-coding sequences of a giraffe to that of an okapi, an animal identical to a zebra, and found it to be closely related to this creature. Besides okapi, the sequences were also set side by side with the gene-coding sequences of cows, sheep, humans, and around 40 other mammals. The results revealed that approximately 70 genes in the giraffe genome showed adaptations that were not seen in any other mammal.The Savannah woodlands in Africa make an excellent home to giraffes, as they feast on the leaves of acacia trees. However, they also fall prey to fierce predators such as hyenas, cheetahs, leopards, and lions. This brings us to the next theory that they use their necks to defend themselves as well. Some researchers even believe that there is evidence that a long-necked giraffe has a significant advantage and is more likely to survive an attack than a shorter giraffe.What did Darwin say about giraffe’s long necks?Multiple methods have been used by experts over the last 140 years to trace the evolutionary history of a giraffe and a giraffe’s ancestral background, the majority of which came from Charles Darwin and his successors or followers. They not only introduced new theories but also developed a range of theories that challenged and questioned theories put forth by their rivals.Darwin was the first scientist to state that giraffes evolved into the elegant creatures that they are today, to help them get access to tender leaves on top of trees. Although many questioned his hypothesis initially, after reviewing his fieldwork and other work papers, it became clear to many that Darwin was on the right track and that he really knew how evolution and natural selection genuinely worked, proving Lamarck’s beliefs on how evolutionary change occurred as incorrect.In his book, ‘On The Origin Of Species’, Darwin wrote that a giraffe has a lofty stature, an elaborate and elongated neck, a head and a tongue, and forelegs, all of which evolved to adapt to its new lifestyle and reach higher branches of trees. Fossil evidence supports Darwin’s theory even more, as it appears that their long necks began developing some 12-14 million years ago, a period where the whole of Africa went through general aridification.What other adaptations have giraffes developed?Besides just feeding on leaves and grazing on grass, giraffes have developed several skills for their survival.Some scientists have put forth an interesting theory suggesting that giraffes, especially the long-necked ones, point their heads and stretch their necks towards the sun. In order to protect their skin from the scorching heat, which helps them remain cool, survive in the harsh climate, and regulate their body temperature efficiently.While drinking water, they tend to lose balance and sometimes even faint because they have to lower their heads to do so. Therefore, giraffes developed a pumping mechanism to prevent fainting. The mechanism developed in their hearts, because of its incredible strength. Their hearts can maintain a blood pressure far greater and better than that of humans.Necking And Other Ways Giraffes Use Their NecksSome theories put forth by scientists strictly suggest that the long necks evolved and are used only to reach the leaves on tall trees.Some others suggest that besides using their necks to fulfill their dietary needs and feed themselves, a giraffe also uses it to attract or impress a potential partner or display sexual readiness, it is said that its neck is ‘sex selected’ and male giraffes whack each other with their necks to impress and win over any females nearby during the mating season. This process is called necking. They also use the back or upper part of their well-armored skull as a club to attack the ribs, chest, and legs of the opponent to knock their balance or leave them unconscious.Males with longer necks have an advantage over their opponents, usually win the fights, and are selected by the females because they’re more likely to pass down their long neck genes. However, this is just a popular theory, and no research or investigation has found strong evidence supporting it.Even though the body mass of males differs from females, their necks are only slightly longer than females. Therefore, there is no significant difference or obvious sexual dimorphism in neck length.Because of its long neck and its long legs, the giraffe’s height allows it to spot any predatory attacks from a distance and thus be safe.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for why do giraffes have long necks, then why not take a look at why do bulls have nose rings or Zebra facts?
Giraffes are fascinating animals that appeared around 16 million years ago and are said to have possibly evolved from antelopes.
