You must be acquainted with natural incidences of biological development occurring around. Zoological and botanical worlds are continuously passing through development process, but the process of development is not taking place everywhere with equal pace. At one place it is occurring rapidly i.e. it gives the consequence with a little time taking and at another place it takes thousand years of time.
Agro-scientists have brought miraculous revolution in the field of agriculture by developing various kinds of hybrid crops. It is amazing that the wheat, which was available fifty years ago in India, had only five to ten times productive capacity. In the olden days, when a farmer sowed one kilogram wheat seeds on his field, he could hardly get five to ten kilogram produce, but agro-scientists have developed hybrid wheat. Now one kilogram hybrid wheat can give sixty to seventy kilogram produce. This has become possible by the technique of development process. Likewise experiments were also carried out on the varieties of fruits and vegetables that yielded good results. You may have also seen that number of varieties of rose is available in the nursery. Some new kinds of plants have also been developed in nursery that can remain alive without sunlight in your home. Beautiful, mind blowing, colourful flowers of different shapes bloom in the same plant now-a-days. This did not happen in ancient time. How does it become possible ? The reason is that scientist made out the process of development and put their steps towards desired direction.
Likewise there are many interesting instances of development process of creatures as well – such as being long the neck of giraffe, being strong the legs and wings of ostrich. All these did not take place suddenly; on the contrary it occurred by very slow process of evolution. Modern scientists have carried out many experiments on birds and animals as well and developed improved breed of animals, which are very useful and advantageous for us.
The nature is extremely mysterious. The process of development is going on continuously – be it rapidly or slowly, but it is developing. At one place consequence is appeared hastily and at another place changes are appeared after passing many years and generations. There also exist some creatures on the earth, which are presently as same as like million years ago, even their perspective and size did not change. For example, take a lizard and scorpion. You will become surprised to know that the fossils of lizard and scorpion of million years ago which we have found, reveals that their shape and size were as same as today. Likewise number of plants also exist today in their same shape and structure as they were millions of years ago.
In a nutshell, if you observe the nature in this view, you will come to know that both trends of development and non-development exist in the nature. Some things never change in the process of development, at the same time some changes take place slowly and gradually but sometimes wonderful alteration takes place as Metamorphosis.
There are following three principles for describing the biological development process, by which it can easily be understood :-
- The theory of Evolution by Charles Darwin
- The theory of Genetics or Inheritance by Gregor Mendel
- The theory of Ecology and Environment
Charles Darwin say that the present form of men, birds, animals, plants which we are looking today, it was quite different at its ancestry stage. He concluded that biological development is a result of evolution. This became not possible by revolutionary change or sudden revolution. Evolution of creatures takes place gradually as per the demand of nature, environment, necessity, social – cultural structure and arrangement. He explained his view by giving an example of giraffe that the neck of giraffe was not as long as of succeeding generations. The length of preceding giraffe was normal, but later on their succeeding generations had to depend upon the leaves of trees because crisis of grass on the land. They used to eat the leaves by uplifting their neck. As a result the development of their muscular and skeleton system occurred on this line and got continuously evolved in their succeeding generations. In this way their neck became so long.
Fig. 1 : Charles Darwin : Inventor of Evolution theory
Fig. 2 : Gregor Mendel : Inventor of Genetics
In the same manner, evolution took place in the men and other creatures. Their present perspective is the result of evolution process. The theory of Charles Darwin earned great name and fame in the world of science. This theory became very successful in defining the process of evolution, but it could not succeed to explain all aspects of development process.
After Charles Darwin, Gregor Mendel discovered Genes in 1866 and explained the biological development process on the basis of inheritance. You might have found many similarities in the children born from the same parents or in same family. Sometimes, some astonishing dissimilarities are seen in them such as being different the colour of their iris, skin complexion, the shape of face, being tall or dwarf, and so on. This process goes on generation after generation. In this process some changes are exceptionally noticeable in them such as giving birth to a child with dark complexion from the parents having fair complexion, giving birth to dwarf offspring from tall parents. Sometimes unexpected results also occur to in them. Mandel told that all these are the result of genetics.
Mendel explained the existence of various kinds of plants and colourful butterflies on the basis of this theory. You may have seen that weaver birds are expert in knitting well-woven nests. Have you ever thought from where did they acquire this instinct ? If the weaver bird is detached from its parents and deprived of the opportunity to meet with other weaver birds, even then they will be able to prepare their nest as beautiful as earlier. They do not need any assistance, suggestion or training. The effect of genes works behind the intellectual skill of weaver birds and this instinct is existed in themselves from their birth (on the basis of genetics). In this way intellectual skill gets transmitted spontaneously from one generation to another by means of genes through genetical development. In this process parental merits and demerits of the genetics are also appeared naturally in their offspring.
The interesting journey of the origin and development of human may be explained on the basis of evolution theory given by Charles Darwin and the theory of genetics by Gregor Mendel.
Moreover, Ecology and Environment both play an important role in the development of man. Ecology and environment provided a new direction and firm base to human development, which was helpful in attaining present perspective. The human, who exists today in so much developed form is not the consequence of sudden occurrence; on the contrary it is a delightful and pleasant result of biological development process, which is occurring in the courtyard of nature with very slow spontaneous pace. This process is still on progress even today and ongoing as usual.
