Название | The Last Giants |
---|---|
Автор произведения | Levison Wood |
Жанр | Биология |
Серия | |
Издательство | Биология |
Год выпуска | 0 |
isbn | 9780802158482 |
Over the centuries, elephants have variously been revered, feared and worshipped – their image being used to symbolise all that is great and powerful.
In 1255, the King of France gave an elephant to the English monarch King Henry III as a unique gift. It was kept in the gardens of the Tower of London, and medieval Londoners flocked to see the mysterious beast. While confined to the lawns of the metropolitan fortress, it was said that the elephant was fed prime cuts of beef and rather enjoyed a bucket of red wine. It’s no wonder he is reputed to have died from obesity. Nowadays the tower hosts a sculpture of the poor creature, peering down from its haunted walls.
Napoleon commissioned an artist to design an elephant monument to be built outside the Bastille. It was meant to be an enormous bronze sculpture demonstrating the emperor’s power in Africa, but it never got past the plaster-cast model stage, which ended up being abandoned, and the project eventually came to symbolise futility and folly in Victor Hugo’s Les Misérables.
Many African nations, including South Africa, use elephant tusks in their coats of arms to represent wisdom, strength, moderation and eternity. The elephant is symbolically important to the nation of Ivory Coast, whose heraldry features an elephant head as its focal point, and in the western African Kingdom of Dahomey (now part of Benin), the elephant was associated with the nineteenth-century rulers of the Fon people, whose flag depicted an elephant wearing a royal crown.
In Denmark, there is a chivalric order called ‘Order of the Elephant’, which is the country’s highest honour, usually bestowed only upon monarchs and heads of state. Indeed, Her Majesty Queen Elizabeth II is herself a ‘Knight of the Elephant’.
Even across the pond, the elephant is still visible in everyday politics, having become the symbol of the Republican Party – a throwback to Aesop’s Fables and the story of the Rat and the Elephant.
Elephants feature in our thoughts and our language. If someone says, ‘Think of a big grey animal,’ you are most likely to think of an elephant, rather than a hippo or rhino, wolf, tapir, gorilla or seal. Elephants have become their own idioms: a ‘white elephant’ being a burdensome thing that’s difficult to get rid of; whilst an ‘elephant in the room’ is the inconvenient truth that nobody wants to speak about.
Elephants have been written about, painted, mocked and allegorised for millennia. Elephants have featured alternately as a symbol of natural might, of fearsome magnitude, peaceful coexistence and utilitarian commercialism.
They have been background extras and leading characters in books for over 2,000 years. Elephants represent nature at its biggest: they symbolise wilderness but also danger, fear as well as courage; they personify war and peace; brute force and the height of intellect. Children love elephants, and adults love them too, because elephants, for as long as we can remember, represent us.
Over 100 million years have passed since the common ancestor of humans and elephants – a small, shrew-like animal – walked the earth. We diverged at a time when dinosaurs still ruled the world, yet we maintain a fascination with elephants that is hard to define, our fates seemingly intertwined throughout history.
From their huge size and strange appearance to their extraordinary senses and incredible brains, it appears that everything about them is unusual, extreme, or unique, and yet in so many ways they are more like us than we would care to admit. They are without a doubt one of the most remarkable and fascinating creatures on earth.
Ancestors and Evolution
Looking at their body size, where they live, and the kind of environments that they live in, it would be easy to assume that the closest living relatives to elephants would be other megaherbivores, such as rhinos and hippos. But in fact, genetic analysis has revealed that the closest living relative of the elephant is the rock hyrax – a furry, rodent-like creature that looks a bit like a guinea pig and isn’t much bigger.
Elephants, along with hyrax, and, believe it or not, the aquatic manatees and dugongs, belong to the branch of mammals known as Afrotheria, which simply means ‘African beasts’. This ancient group split off from other mammals at a time when Africa was an island continent, probably during the Cretaceous geological period, tens of millions of years before Triceratops and Tyrannosaurus dinosaurs were thundering around the American plains!
Given the long evolutionary history of the Afrotheria, surprisingly few living mammals fall into this group, and those that do are exceptionally diverse. As well as the elephants, hyraxes, and manatees, Afrotheria also includes elephant shrews, golden moles, and tenrecs, which are shrew and hedgehog-like mammals that are mainly found on Madagascar. The group is unique in that is contains one of the smallest living mammals, the long-eared tenrec, which weighs just 5 grams – not much more than a penny coin – as well as the largest, the African savannah elephant. It was only thanks to scientific developments in genetics over the past twenty-five years that we had any idea that these animals were in one related group.
While rock hyrax and the other little creatures are native to the hills, plains and valleys of Africa and the Middle East, manatees and dugongs float around in the tropical waters of Central and South America and off the warm coasts of the Caribbean, Indian and Pacific Oceans. Yet, despite their obvious differences, these seas creatures share a number of traits with elephants: manatees are the only herbivorous marine mammal; they have four small nails at the end of each flipper that are very similar to the toenails of an elephant; and they also have a prehensile upper lip that they use to grasp hold of marine vegetation, much like a stubby trunk. They even have similar teeth, with incisors that resemble tusks, as well as the horizontal molar teeth displacement that also occurs in elephants.
Hyraxes have flattened nails, rather than the claws found on most similar-sized land mammals. They even have small tusks too that develop from incisors. And, like elephants and manatees, their mammary glands (which produce milk for their babies) are near their front legs. In all other mammals, except primates, milk teats are found between the rear legs. A final trait shared with elephants is that their testicles stay inside the abdomen, rather than swinging around like a monkey, bull or human. So, despite the aeons since the common ancestor of these species was alive in the swamps of North Africa, there are still plenty of visible clues to their shared heritage.
Fossil evidence helps us to work out when the anatomical features of living elephants evolved, and why. If we were to journey back over 35 million years ago to Northern Africa, we might be fortunate enough to see a pig-sized animal that looked somewhat like a modern-day tapir, foraging in the soft vegetation around rivers and lakes. This was Moeritherium, one of the earliest proboscideans – the group within Afrotheria that specifically contains elephants and their relatives.
Moeritherium died out without leaving any descendants, so it is not a direct ancestor of today’s elephant species, but they shared features with other proboscideans, like a flexible upper lip, which, like a modern trunk, was used for grasping and handling food. They also had short tusks, although these were more tooth-like than the tusks of a modern-day elephant.
Part of the skull and teeth of another very old proboscidean – Eritherium – was recently discovered in Morocco. It is dated to 60 million years ago, which was a time of rapid evolution and change for mammals following the demise of the dinosaurs. Eritherium was tiny, standing only 20 cm high, no bigger than a well-fed domestic cat, making it a thousand times lighter than a modern African elephant. But, despite appearances, it was its unique teeth that allowed scientists to identify it as the earliest ancestor of the elephant!
Other than humans, the evolutionary history of proboscideans is one of the best-mapped mammalian lineages, with around 175 species identified. They are divided up into five main groups,