Adaptation may be defined as a state of life in harmony with the external environment.It is Evolution of characteristics that makes a group of organisms more suitable to live and reproduce in their environment.In the plant world we see a vast variety of physical manifestations which indicates adaptation, such as type and size of leaf, presence of hairs, size of plant which facilitate life in wet or dry ground, in sunny or shady places and the like.Generic adaptations usually provide responses to environmental changes. Adaptation is generally a compromise result between different selective forces and therefore it is not a perfect, but rather optimal solution to survival problems and is always related to a particular environment.
Animals are similarly adapted, the goat to its mountain, the tiger to its jungle, the mole to its burrow. Even sheep are adapted to certain kinds of pasture and may die if moved. This is true particularly of older sheep. Young animals become adapted more easily. Certain birds which do not adapt easily, like the swallow, must escape to warmer climes in winter. While in their proper environment animals flourish. If they are suddenly moved to another environment their lives may be in danger, especially from inclemency of climate, from difficulties in securing food and lack of adequate physical means of protection. Just as there is an adaptation of form there is an increasing adaptation of reaction, the animal becoming more and more capable of surviving by adapting itself to changing environments until in the case of man adaptation is remarkably complete.
What Does Adaptation Meant In Animals, Biology And Evolution ?
Such matters are taken into consideration by those who are concerned with mass movements of troops or the transfer of animals from one place to another. Animals from the tropics are brought to our zoological gardens in the summer and may at first need artificial heat. The “ trooping season ” is in autumn and spring for similar reasons. An essential feature of adaptation is that it takes time. If time for slow’ adaptation is permitted it is quite remarkable to observe the adaptation which animals will show.
The monkey, accustomed to a hot climate, will eventually adapt itself to the rigors of a British winter. Man may live safely at 25,000 feet if he reaches that height slowly, but if he goes rapidly in an aeroplane without a supply of oxygen he may die.
Man can by artificial means, such as warmth and clothing, adapt himself more readily than the lower animals, but under extremes of climate a considerable proportion show themselves less adaptable than others. This is well seen in relation to exposure to heat, cold and high altitudes, but is also applicable to hard physical or mental work.
We recognize also the phenomenon of mental adaptation in a general sense when an individual goes to a new community, notably a child who goes to boarding school. The house-master may report that he is or is not “ settling down ”, and the same term is used also in regard to adults who adapt themselves well to the conditions of new posts. Some men mellow with age like wine or the bricks of a new house. They strike less harshly the palate or the landscape. All are affected to some extent by their environment.
If the animal is in harmony with its environment it lives healthily, happily and long, but if not a series of reactions is seen. The power of mental adaptation varies, however, enormously in different persons. The “ good mixers ” and the very adaptable people of the world are well recognized, and so too are those who are obviously difficult and will not adapt themselves to enforced surroundings and company. It is common to look upon such persons merely as unfortunates, but it is less often realized that they are really doing their best to adapt themselves but are held back by forces over which they have but partial control, and they may themselves be the subjects of great mental anguish in the effort. Usually it is that in such persons the mental adaptation is a slow process, and this may so seriously interfere with the social reactions of the individual that steps must be taken to accelerate it.
Effect of lack of mental adaptation is dealt with in relation to “ Conflict ” where it seems that just as excessive heat, cold, high altitude or necessity to work hard or to fight bring about the bodily reactions which we group under the heading of increased sympathetic activity iu animals, so also in man lack of mental adaptation brings about exactly the same bodily effects which if continued will have a seriously harmful effect on the happiness and health and length of life of the individual if not lead to his restraint in an asylum.
Thus it becomes evident that general biological principles apply to all living things, plants or animals, and that there must be adaptation or there will be a stunted, unhealthy, unhappy existence and a shortened life. Plants when growing in poor soil tend to flower rapidly and reproduce excessively, bacteria in similar circumstances form spores which are specially resistant to conditions which would kill the parent. Lower animals protect their young to the death, while man when faced with danger to himself such as air raids, makes special provision for the protection of his children. Thus we see a provision for the continuance of the species when adaptation is incomplete as if the living organism never despaired of the world being a better place for its descendants.
It is, however, not to be understood that the best adapted humans are necessarily the most evolved. Those who strive to make the world a better place are constantly in conflict for their ideals are probably on the highest plane.It is convenient to consider adaptation as taking place at three levels: the reflex, the instinct, and the mental, according to the standing of the animal in the phylogenetic scale.
The reflex is an immediate response which depends on the nervous system and from its study it is possible to obtain some idea of the fundamental processes of the system. Instincts are more elaborate innate reactions of obvious value to the animal while mental activity involves some degree of thought.
These various levels of activity merge insensibly into each other and overlap and, as we shall see, in human mental activity all these levels are involved.We may then consider the function of the nervous system, the instincts and the mind in relation to adaptation.“ Man—an adaptive mechanism ” is described by Crile.
Adaptation is, at the same time, the result of an evolutionary process and the basis for a subsequent evolution. In this context it should be noted that some hereditary characters, not necessarily beneficial, can represent pre-adaptation, which can acquire survival value under changed environmental conditions or allow expression of new ways of life. For example, the palm-shaped legs of many mottled birds, adapted to muddy soils, can represent a pre-adaptation to swimming.