During the last two centuries, science has enjoyed a meteoric rise in popularity. Amazing scientific discoveries have enthralled generations and increased materialistic comforts beyond the public imagination. As a result, people increasingly view science as the holder of unequalled power capable of achieving anything. Therefore, one may argue that we should turn to science for obtaining solutions to the present day problems. However, the current state of scientific knowledge is full of gaps and blanks. Therefore any beliefs and inferences based on it are liable to be changed.
Science has been incapable of providing definite conclusions in many areas. For example, initial theories regarding the nature of atoms and molecules had to be modified as new discoveries provided novel insights into their structure and function. The science of matter is yet to be completely elucidated. The author of On the Limitations of Science, J. W. N. Sullivan, writes that although our present knowledge of Nature is much richer than in any previous era, it is insufficient because no matter where we turn, we are faced with ambiguities and contradictions. This reality becomes strikingly apparent when we consider the obscure scientific views on the definition of life, the origin of life, the evolution of various organisms, consciousness
and personality development.
What is life?
More often than not science has left many questions unanswered. One of them is defining and understanding the process of life and death. The issue of an unequivocal distinction between living and non-living, animate and inanimate has confused scientists for centuries and is still unresolved. The Concise Oxford Dictionary defines life as:
"The condition which distinguishes active animals and plants from inorganic matter, including the capacity for growth, functional activity and the continual change preceding death."1
In The Penguin Dictionary of Biology, we find:
"Life. Complex physico-chemical systems whose two main peculiarities are (1) storage and replication of molecular information in the form of nucleic acid, and (2) the presence of (or in viruses perhaps merely the potential for) enzyme catalysis."2
Perhaps if we ask the expert scientists who study the origins of life, we may get a clear view on the definition of life. But even they are confused about it. As Antonio Lazcano writes in Early Life on Earth,
"An all-embracing, generally agreed-upon definition of life has proven to be an elusive intellectual endeavour…"3
The book The Molecular Origins of Life contains a comprehensive scientific discussion, by leading experts in the field, of how life might have evolved, but nowhere does it define life.
If we review the scientific literature on this subject, we find that scientists only speculate as to how life could be defined but are never sure of their own view. They give a very general and broad description of life in terms of growth, reproduction, metabolism, motion and response. Scientists seem to be following the attitude "it is sometimes easier to study a subject than to define it" of Nobel Prize-winning chemist Linus Pauling, avoiding a consensus on defining life.
A very crude and superficial classification of living and non-living that appears in standard textbooks is that humans, animals and plants appear and behave differently than stones, sand, etc. This line of distinction becomes blurred when stationary, lifeless objects exhibit occasional life-like features and living organisms exhibit lifelessness. Thus, problems in exactly classifying systems as living and non-living arise because (1) there are systems which are considered to be alive but do not exhibit all of the classical properties, and (2) there are non-living systems that display these properties. Organisms that exhibit "cryptobiosis" belong to the first set. Examples from the second set are fire and atoms of matter. Let us consider these systems briefly.
The phenomenon whereby living organisms that exhibit lifelessness during their life cycle is described as cryptobiosis (Latin; meaning "hidden life"), a puzzling natural phenomenon. When an animal or plant becomes so inactive that its life processes almost come to a halt, it is said to enter cryptobiosis. There are a surprising number of organisms that undergo cryptobiosis, including plants (as seeds), the eggs of some crustaceans and small water creatures called tardigrades. Inactive tardigrades can be preserved in a bottle for many years, where they would appear to be dead. Movements can be elicited in them by the addition of water to the bottle.
An article published in March 1983 issue of Science Digest magazine described a study of the time lapse photographic snaps of the bottom of the sea, which revealed some amazing facts. An inanimate object like a stone remained motionless at the bottom of the sea for three months. Then it suddenly ascended one foot above the bottom surface and remained stationary for few hours. It then descended back to its original position. A hand-like texture appeared in another stone. It displayed movements for 12 hours and then remained motionless for 6 months....