An adaptation is a type of mutation, or change in an organism's genes. Genes can be thought of as instructions that are passed down from parent to child. They shape how living things look and behave. An adaptation helps an organism, such as a plant or animal, survive in its environment. The mutation is passed on from one generation to the next. As more and more organisms inherit the mutation, it becomes part of the species. The mutation has become an adaptation.
Structural And Behavioral Adaptations
An adaptation can be structural, meaning it is a physical part of the organism. An adaptation can also be behavioral, affecting the way an organism acts.
An example of a structural adaptation is the way some plants have adapted to life in the desert. Deserts are dry, hot places. Plants called succulents have found a unique way to survive there. They have adapted to the climate by storing water in their thick stems and leaves.
Animal migration is an example of a behavioral adaptation. Gray whales migrate thousands of miles every year. They swim from the cold Arctic Ocean to the warm waters off the coast of Mexico. Gray whale calves are born in the warm water. Later, they travel in groups to the nutrient-rich waters of the Arctic.
Some adaptations are called exaptations. An exaptation is an adaptation developed for one purpose but used for another. For example, feathers were probably adaptations for keeping animals warm. Later, they were used for flight, making feathers an exaptation for flying.
Adaptations usually develop in response to a change in an organism's habitat.
The English peppered moth is a famous example. Before the 1800s, the most common type of this moth was cream-colored with darker spots. Few peppered moths displayed a mutation of being gray or black.
As the rise of factories changed the environment, the appearance of the peppered moth changed. The darker-colored moths became less rare. In fact, they began to thrive in the smoky cities. Their sooty color blended in with the trees stained by industrial pollution. Birds couldn't see the dark moths, so they ate the cream-colored moths instead.
Sometimes, an organism develops an adaptation or set of adaptations that create an entirely new species. This is known as speciation.
One way this can happen is through the physical isolation of a species.
A good example is the wide variety of marsupials in Oceania, the area that includes Australia and New Zealand. Long ago, this region was part of Asia. Before it broke away, marsupials arrived. Marsupials are mammals that carry their young in pouches. They are distinct from placental mammals, which carry their young in the mother's womb. Marsupials are now the main type of mammal in Oceania. Meanwhile, placental mammals are the main type on every other continent.
Koalas are one of the most famous marsupials. They adapted to feed on eucalyptus trees, which are native to Australia. The extinct Tasmanian tiger was a meat-eating marsupial. It adapted to fill the role played by big cats such as tigers on other continents. Marsupials in Oceania are an example of adaptive radiation. This is a type of speciation where species develop to fill empty roles in their environment.
Organisms sometimes adapt to and with other organisms. This is called coadaptation. Certain flowers have adapted their pollen to appeal to the hummingbirds' tastes. Hummingbirds have adapted long, thin beaks to collect the pollen from certain flowers. In this relationship, the hummingbird gets food, and the plant's pollen gets distributed. The coadaptation helps both organisms.
Mimicry is another type of coadaptation. With mimicry, one organism has adapted to resemble another. For example, the harmless king snake has developed a color pattern that resembles the deadly coral snake. This mimicry keeps predators away from the king snake.