Chapter 1

Introduction

Information is central to life. The principle enunciated by Crick, that information

flows from the gene (DNA) to the protein, occupies such a key place in modern

molecular biology that it is frequently referred to as the “central dogma”: DNA

acts as a template to replicate itself, DNA is transcribed into RNA, and RNA is

translated into protein. Genotype thus implies phenotype, seen as the ensemble of

proteins and germane structures constituting an organism. Nevertheless, since pro-

teins are required for the decoding of DNA into protein structures, the linear flow of

information implied by the central dogma is clearly only part of the story.

The mission of biology is to answer the question “What is life?” For many cen-

turies, the study of the living world proceeded by examination of its external charac-

teristics (i.e., of phenotype, including behaviour). This led to Linnaeus’ hierarchical

classification. A key advance was made about 150 years ago when Mendel established

the notion of an unseen heritable principle. Improvements in experimental techniques

lead to a steady acceleration in the gathering of facts about the components of living

matter, culminating in Watson and Crick’s discovery of the DNA double helix half a

century ago, which ushered in the modern era of molecular biology.

The mission of biology remained unchanged during these developments, but

knowledge about life became steadily more detailed. As Sommerhoff has remarked,

“To put it naïvely, the fundamental problem of theoretical biology is to discover

how the behaviour of myriads of blind, stupid, and by inclination chaotic, atoms can

obey the laws of physics and chemistry, and at the same time become integrated into

organic wholes and into activities of such purpose-like character”. Since he wrote

those words, experimental molecular biology has advanced far and fast, yet the most

important question of all, “what is life?” remains a riddle.

It is a curious fact that although “information” figures so prominently in the central

dogma, the concept of information has continued to receive rather cursory treatment

in molecular biology textbooks. Even today, the word “information” may not even

appear in the index. On the other hand, whole chapters are devoted to energetics

© Springer Nature Switzerland AG 2023

J. Ramsden, Bioinformatics, Computational Biology,

https://doi.org/10.1007/978-3-030-45607-8_1

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