How and why are dolphins so smart
Dolphins belong to an order of aquatic mammals that diverged from hippopotamus and other ruminants 50 million years ago. They have always entertained seafarers through their amazing leaps and feats. But these mammals rank second in the most intelligent animals. Their encephalization quotient(weight of brain to the body) is only second to that of humans. For centuries scientists debated over the factors that made dolphins so intelligent. Let us now dive into the world of dolphins.
Origins of dolphins Dolphins are Cetaceans. These Cetaceans diverged from even hoofed ungulates some 50 million years ago. Hippopotamus might be the closest living relative of all cetaceans. In the beginning their ancestors had legs like land animals. But few million years later they developed a jaw that sent vibrations to their earbone. This helped them go fully aquatic. Gradually their limbs became fins and they developed a blowhole to squeeze water out. Their genital organs were kept hidden by two slits. Thus a fully aquatic dolphin evolved from a terrestrial herbivore. But what brought upon this massive step? There is no clear answer. Some say that due to adverse conditions on land, these mammals fled to sea and thrived there. While others believe that they ventured to sea in search of better feeding grounds. Whatever the reason maybe, dolphins emerged out as excellent predators in the seas and rivers of the world.
How smart are dolphins actuallyDolphins stand next only to Chimpanzees in the list of most intelligent animals. Their brain too is split into two hemispheres like ours, showing that they too have separate parts of brain pertaining to separate functions. That being said, how smart are they?
- They are observed engaging in complex hunting strategies with an awesome teamwork. Dolphins are very social and they signal each other a lot during hunting, making sure that every hunt is successful
- Dolphin calves stay with their mothers for a long time, up to 8 years. Young dolphins learn a lot in this time. Mothers can be seen cuddling and playing with their young
- Dolphins can recognize themselves in mirrors. That shows that dolphins are self aware.
- They can learn tricks very quick. They can even invent new tricks or improvise with what they know to get rewards. Despite having no free limbs, dolphins are amazingly adept in using and making tools. They are seen shoveling the sea bed with sponges(aquatic organisms) to get to their hidden prey. In captivity they use variety of human-made tools from rings to balls
- Dolphins show empathy. They even mourn their dead
- Dolphins have friends. This sounds fairly normal, but developing a strong bond with a non related member of a pod/group is very rare even in other social animals.
- Other than humans, only dolphins are the animals known to have pleasure. They have a concept of pleasure and leisure which in itself is amazing. They are seen engaging in recreational sex, getting high on puffer fish venom, games with their prey, etc
- They probably give each other names. It is observed that some dolphins respond at a particular whistle given by another dolphin
- Dolphins have accents. Each pod of dolphins seem have to have their own unique songs and whistles
- They probably engage in gossips.
- Just like apes, dolphins mimic human actions. In 1985, a scientist studying dolphins was just playing around with a weed. He put the weed on his head like a crown and acted like Poseidon, the God of oceans. He then threw the weed out into the sea. Soon a dolphin came to the surface with the weed on its head. This was the first time mimicking aspect of dolphins was recorded.
- Dolphins can operate two hemispheres of their brain separately. This enables them to sleep with one eye open. Unlike humans their brain has only 3 lobes. It is thought that this enables them to process their senses quicker than humans as all the senses are sent to different parts instead of one.
- They can easily solve complex puzzles.
Given with all these accomplishments of dolphins, many countries have decided to categorize them as "non human animals" and have strict laws against hunting, commercially using and eating dolphins.
But why are dolphins so smart ? We humans try to compare animals with human intelligence. This may not be correct. Dolphins have a brain far more intricate than ours, so accurately measuring their capacity is impossible. They might even be smarter than us humans. But what made these deep sea marine mammals so smart in the first place?
- To answer that we need to compare them with other intelligent animals like humans, chimps, elephants, crows, parrots, pigs and dogs. What do all of these animals have in common? They are all very social. Not all herding animals are intelligent again. Only a society that actively interacts with itself and other societies is responsible for smarter brains. Interacting and communicating expands the cerebral cortex of an organism, allowing its brain to be bigger. Traits like empathy and altruism too develop as an organism becomes more social. Maybe the intricate relationship with its pod is what made a dolphin smarter ultimately
- By peeking into the evolution of human intelligence too we can derive some interesting conclusions. The fruitarian ancestors of humans had larger jaws to munch on leaves and fruits. But as we developed a taste for meat, our jaws reduced in size, leaving more space for brain to occupy. No matter which mammal species you are, smaller jaws in comparison with body, means bigger brain. The same might be true for modern dolphins, who have very small teeth and a streamlined jaw. They have protruding jawbones that help them out with echolocation. This made more room for their brains to develop.
- Around 35 million years ago, the waters of Earth began freezing because of a global temperature drop. This made food less available for the ancestors of dolphins. So they shrunk in size and developed smaller sharper teeth to settle with smaller prey. This is the reason why dolphins have small teeth. This global cooling might also be a factor in making dolphins intelligent.
- Just like humans, having lesser natural predators favored dolphins by allowing them to experiment with their surroundings making them smarter.
- Living in the seas, among viscious predators, might have forces dolphins to develop such complex brains.
- Dolphins can be pregnant for twelve months, giving birth to a fully developed calf. Animals with longer gestation periods like elephants, usually are more intelligent. This calf can be nursed by its mother for one whole year. It then resumes with its pod for seven or more years, learning essential skills. This type of upbringing and birth might also be crucial factors for dolphin intelligence.
- Dolphins as we know them today, have been on this planet for 15 million years. This mindboggling amount of time was well utilised by them. They got to learn a lot from their experiences which they propagated to their progeny
All of these factors could have collectively been responsible for making dolphins so intelligent. For centuries these magnificent beings have been revered by humans. Ancient Greeks, Egyptians, Indians, Chinese and South American tribes, all connected dolphins to divinities. Dolphins are thought to be vehicles of Poseidon, Greek God of oceans. Indian river goddess Ganga rides on a white river dolphin. The zodiac sign of Capricorn is thought to represent a dolphin. These altruistic intelligent creatures are meant to be loved and respected.