Dolphins are a highly evolved species. Over the years they have adapted themselves to thrive in different climates and to make the most of their maritime habitats. Most species of dolphin can swim or dive for 1000 feet without needing to come up for air. This means that they can cover huge distances quickly, without being slowed down by their need for oxygen.
The iconic shape of the dolphin is another feature which has evolved over centuries. Many years ago, dolphins’ bodies were much straighter which made it more difficult to flee from hungry predators. The bow shape which we associate with dolphins today is one of the dolphin adaptations which allows them to swim much faster, making it easier for them to catch food on the move and to stay out of the way of creatures which could harm them.
Dolphin fins used to be made out of bone which made them rigid and inflexible. They have now adapted to have fins made of stiff cartilage. This cartilage preserves the important aerodynamic shape of both the dorsal and pectoral fins but crucially allows them to move. The fins have adapted to include a layer of muscle, which allows the dolphin to control the way in which water flows around its body, increasing agility and speed and reducing the amount of energy required to move through the water. Dolphins are disadvantaged by being mammals and needing to breathe in oxygen to survive. They have had to adapt the way in which they take in and use their oxygen supply in order to become much more efficient at surviving in their habitat. To do this, the heart has evolved to beat at a slower rate. Some dolphins have been recorded to have a heart beat which is as slow as 12 beats per minute. Dolphins have adapted to produce a protein called myoglobin in their muscles. This protein helps to store oxygen in the muscles themselves, so that they can use it only when they need to use it most, ie. when diving.
Dolphins have incredibly good eyesight. They can see both above and below the water’s surface: a skill which is practically unheard of in the animal kingdom. Over time, dolphin’s eyes have adapted to secrete an oily substance which protects them from the harsh salt water.
Their skin is another one of the dolphin’s adaptations which has evolved in order to help dolphins make the most of their environment. It has become smoother which reduces resistance in the water and helps them to swim faster and change direction more easily in the water.