A World Without Color

When you think of a koala, you likely picture a furry gray or brown critter.  But some koalas are born with white fur and red eyes. Why? It’s because of a condition called albinism. That’s an inherited condition in which the body can’t properly produce a pigment called melanin. Melanin is what gives color to many animals’ skin, fur, feathers, and eyes.

Albino animals are mostly colorless. This can make them look striking. But it can also make their lives challenging in the wild. 

Koalas are not the only creatures that can be born albino. More than 300 kinds of animals in North America, as well as many other species around the world, have albinism. But it’s rare. Only about 1 in every 10,000 mammals are born with the condition. It also affects 1 in roughly 20,000 people in the U.S. 

Albinism is an inherited trait. Most animals inherit the genes that contribute to their coloring from both parents. Genes are found inside cells, the tiny units that make up an animal’s body. Genes carry information that determines traits such as eye, hair, and skin color.

Most animals inherit two copies of each gene—one from each parent. If an animal inherits at least one typical pigment gene from one parent, it will likely have typical coloring. But an animal must inherit two genes for albinism in order to be colorless. That’s part of what makes the birth of a colorless animal so rare. 

Animals with typical coloring, like two gray koalas, can produce albino offspring by each passing down a gene for albinism. And an albino animal can still have babies that produce melanin. 

Not all white animals are albino. There are many normally white creatures, like polar bears. One big clue is eye color. True albino creatures don’t produce dark eye pigments.

Melanin also helps the eyes function, so albinism weakens eyesight. That can make it hard for albino critters to find food and spot predators. 

Plus, melanin helps protect the skin from the sun’s damaging ultraviolet rays. Animals and people who are born without melanin are at greater risk of sunburn and other skin problems. 

Scientists continue to study albino animals. They hope to help the creatures survive in the wild.