Polar bears, also known as Ursus maritimus, are the largest land-dwelling carnivores in the world and inhabit the icy waters of the Arctic Circle. They are well adapted to the harsh, arctic environment, and are one of the most unique species in the animal kingdom.

An adult male polar bear can weigh anywhere between 300-800 kilograms and can stand at a height of 1.6 meters. Unlike other bear species, the polar bear does not have a shoulder hump, and its head is smaller in comparison with small, round ears and a slender neck.

The skin of the polar bear is black and its fur is transparent, which gives it its signature white appearance. However, their fur can sometimes take on yellow or other hues. Each paw of the polar bear has five toes and non-retractable claws, which help it traverse the ice and swim efficiently.

The preferred habitat of the polar bear is the Arctic sea ice floes, which provide ample hunting opportunities. Polar bears are solitary creatures, with the exception of mating and lactation periods. They spend the majority of their time inactive, but they are excellent swimmers and will traverse great distances in search of food.

Their diet primarily consists of seals, as well as larger species like walruses and beluga whales. They may also eat fish, seabirds, small mammals, and even carrion on occasion. Polar bears supplement their diet with berries and plant roots in the summer and seaweed near the coast in the spring and summer.

When the Arctic sea ice melts in the summer, polar bears are forced to spend time on land, where they must rely on their stored fat to survive. This can lead to periods of starvation, especially if the sea ice does not freeze soon enough in the autumn.

The white fur of the polar bear acts as a form of camouflage in the snow and ice, helping it blend in with its surroundings and increasing its chances of successfully hunting.

The polar bear is thought to have diverged from the Irish brown bear, which has a similar genetic background due to its proximity to the Arctic Circle. The white color of the polar bear's fur is a result of a genetic mutation that has been naturally selected for over time.

The hairs are hollow, and their inner walls are rough, which causes complex reflections, refractions, dispersions, and other optical reactions when light passes through. This results in only ultraviolet light being able to penetrate, which keeps the polar bear warm.

Polar bears are a magnificent and unique species that are perfectly adapted to the harsh, arctic environment. Despite the challenges they face, they are formidable predators and masters of survival in their harsh environment.

Whether hunting on the ice or swimming in the Arctic waters, polar bears are truly one of the most remarkable creatures in the animal kingdom.