Emergence of Living Forms | Evolution

The following points highlight the two categories of concept of emergence of living forms. The categories are: 1. Concept of Special Creation 2. Concept of Organic Evolution.

Category # 1. Concept of Special Creation:

The creationists believed that the existing forms of living organisms were brought in their present forms by Divine command. One of the greatest supporters of the special creation doctrine, Father Suarez (1548- 1617) advocated that in six days the earth with animals and plants was brought into being. At the end of the period creation was closed and the living things remained almost as such as they were originally created.

This concept is a static theory in which the living organisms stand still. Certain minor variations may be admitted, but such variations are not enough to produce new forms or species. Until the middle of the nineteenth century European people believed in the special creation and hold the orthodox belief with tenacity.

Category # 2. Concept of Organic Evolution:

Op­posing the static idea stands the evolu­tionary concept. Ever since man started to contemplate nature, exponents of evolu­tionary ideas came into being but only in the nineteenth century that serious obser­vation and experimentation in this line were carried out.

The evolutionary concept holds that nothing is static, but all ani­mate objects are dynamic and are sub­jected to changes. The animals and plants that we see today, have come into exis­tence through a slow and gradual process of transition from old pre-existing forms.

The process of changing is still con­tinuing and the evolutionary concept is dynamic. The concept of organic evolution is regarded by many to be comparatively a recent idea. It is believed that Charles Darwin is the originator or promulgator of the theory of organic evolution.

The doctrine of static creation seemed wholly inadequate to many original thinkers and the idea of evolutionary concept can be traced back to the early Greeks, because the germ of the evolutionary concept had its inception with the Greeks.

Empedocles (495-435 B.C.) is usually regarded as the father of evolutionary concept. He emphasises on the attempts of nature to produce the fittest forms through chance and the elimination of the units. Next to Empedocles comes another Greek intellect, Democritus (460-357 B.C.) who advances the idea of adaptations of struc­tures and organism as a whole.

But the most notable Greek figure is Aristotle (384-322 B.C.) who assumes the existence of an in­telligent design in nature which acts as the perfecting principle.

Aristotle advances the notion that from nonliving minerals plants arose and the plants in turn gave origin to simple animals like sponges. From these lower forms of living organisms arose the higher animals and finally man at the peak through a long and continuous series of transformations.

He emphasises the operation of natural law in the inanimate and animate forms. Gregory of Nyssa, a bishop and a theologian of the fourth century A.D. attempts to make a com­promise between the ideas of the special creationists and the Greek philosophers.

He believed that God imparted the funda­mental properties to the matters. The matters were at first chaotic and without definite forms. Gradually from such disor­ganised materials evolved complete and organised forms of the universe under Divine command.

Saint Augustine (353- 430 A.D.), a church father rejected the concept of special creation and advanced developmental concept. He was the be­liever of change as involved in the forma­tion of complete objects and creatures.

Thomas Aquinas (1225-1274 A.D.) em­braced Augustine’s ideas with much con­fidence. From Aquinas on, a host of workers expressed their views regarding the genesis of living objects. Most of the views are discarded at present, because they add nothing substantial but some of them may be briefly placed here as historical im­portance.

Linnaeus (1707-1778) believed the origin of species through special creation but he advocated the production of post- creation forms by hybridisation. Buffon (1707-1788) regarded that variations in species are caused by the direct influence of environment and the modifications of the structures are’ conserved by heredity.

He puts significance on geographical iso­lation, formation of varieties by domesti­cation (artificial selection). Influence of climate particularly on human races. He throws much light on the existence of struggle for existence to stop overcrowding and thus the balance of nature is main­tained.

Erasmus Darwin (1731-1802), grandfather of Charles Darwin, did not emphasise on the influence of environment in the production of changes, but believed that structural modifications arose as the resultant of reactions within the body of the organisms.

He regarded that all animals undergo transformations and al­most followed the Lamarckian principle of transmission. He first stated the factors operating in the process of inheritance of acquired modifications. Jean Baptise Lamarck (1744-1829) is one of first bio­logists to develop a theory of biological transformation of living organisms and interprets life in term of evolution.

He explains evolution on the principle of use and disuse supplemented by heredity. He believes that acquired characters pass from parents to off-springs. This theory is under great dispute and is unacceptable to modern biologists.

Another Frenchman, E Geoffroy St. Hilaire (1772-1844), a contemporary of Lamarck, believes on the direct influence of environment as the primary cause of evolution. He anticipates the idea of de Vries. Charles Darwin (1809-1882) is undoubtedly the foremost figure in the evolutionary history.

His prominency is not only for the originality of his ideas but he paved the way for the general acceptance of the truth of evolu­tion by Natural Selection as a force in evolution. The publication of his cele­brated book entitled “On the Origin of Species by Means of Natural Selection” in 1859 is the crowning event in biology.

His twenty years observations and researches are shaped into a reasonable theory of evolution. Subsequent investigations have pin-pointed certain shortcomings of Char­les Darwin but the central idea of evolu­tion remains unaltered.

Evolution is possible because living or­ganisms have three primary attributes. The first is the capacity of reproduction, the second is the progressive force which produces mutation and the third is the conservative process which preserves and continues the mutations is the heredity.

If there is no reproduction life would cease to exist, without heredity there would be no continuity from generation to generation and without mutation there would be no variety and living organisms would never have evolved beyond its original, form.