Karen Adair, age 13, of Pocatello, Ids. for her question:
WHAT IS ADAPTATION?
Adaptation is the ability of animals, including human beings, and plants to adjust to their environment or surroundings. Some forms of life adapt more easily than others.
Human beings, as an example, can adjust to many different kinds of environments. They live in all kinds of climates. Human beings are generalized, which means that man's body allows him to adapt more easily to different environments.
But some living things, such as bamboo plants and mosquitos, are more specialized and because of their physical makeups they can live only in warm, rather wet climate.
Most living things simply die when they cannot adjust to their environments. Many kinds of plants and animals that once lived on the earth have become extinct, which means that none of their kind exists any longer.
Living things may adapt to changes in environment in two ways. A population or group of the same kind of organism may adapt through evolution over many generations. This means they change over a number of lifetimes. Or an organism may adapt within its own lifetime by adjusting its behavior or body chemistry in some way.
Adaptation of a population usually happens over thousands or even millions of years Scientists tell us, for example, that the ancestor of the horse was probably about the size of dogs and had short legs and several toes. The horse changed over many millions of years until it is about six times larger than its ancestors and it has long legs with a single toe.
The horse is believed to have evolved because it adapted to changes in is environment. The horse once lived in mountainous places covered with forests. Then, over millions of years, parts of the earth changed and the horse developed into a big, swift animal capable of covering large stretches of open plains in search of food.
Adaptations that occur over a relatively short time are often called acclimatization.
Many human beings must adapt to a different diet, climate or altitude when they move to a new locality. They may be ill for a short time but they soon adapt to the changes in their surroundings.
Adaptations made during a lifetime depend largely on the sensitivity or reactiveness of the organism. And sensitivity usually depends on the kind of receptor or receiving system, such as the nervous system, an organism has developed.
Human beings have a highly developed and sensitive nervous system. We can reason and learn to adapt to many changes in the environment, such as cold weather or a new school.
But every animal and plant has different sensitivities and reacts and adapts differently.
A famous Russian physiologist named Ivan Pavlov experimented with the acquired habits and adaptations of dogs. 8e found that acquired characteristics depend largely on the development of the dog's nervous system and how it was conditioned or trained.