Unlike in physical sciences, the progress in biological sciences was slow almost till the end of 19th century or so. For making meaningful strides, biologists needed tools and techniques so that they could probe the interior of the body, tissues and cells and finally the molecular organization and working of organisms both at organismic and molecular levels. However, the instruments and techniques are typically built by physicists, engineers and chemists/biochemists. Biologists use available techniques in trying to understand the working of organisms at various levels and unravel the mysteries of life. For instance, with the building of simple microscopes, it was possible to see the organisms invisible to the human eye. Once such organisms were detected, it necessitated development of microscopes of various types (compound, florescence, electron, confocal etc.) with higher magnification as well as high resolution. The needed tools and techniques became available around the 19th century and these heralded unstoppable progresses in biology. This article is to cruise through a few major highlights of developments in biology that are of fundamental and great importance.
Firstly, making some considered sense of the vast biodiversity was crucial. This included a systematic way of organizing the vast biodiversity in a systematic way (grouping related organisms), naming them, establishing relationships between different groups of animals and plants, as well as understanding the hierarchy within plant and animal kingdoms; all this became possible through the work of Carl Linnaeus (1707-1778) who proposed the system of binomial nomenclature (name of the genus followed by species- ex: Homo sapiens). He is regarded as the father of Taxonomy. In fact, orderly arrangement (identification, classification and documentation) of biodiversity became largely possible due to Linnaeus. Prior to 19th century, in general, biological studies were largely limited to describing fossils, morphology, anatomy, physiology, development and so on.
An important breakthrough was the proposal of a generalized theory called “Cell Theory” (1839) which stated that the cells are the fundamental units of all life forms. It is the result of several workers like: Robert Hooke (1665); T. Schwann & M. J. Schleiden (1839). Soon thereafter, Rudolf Virchow (1865) showed that cell arise from preexisting cells only (by cell division) and not de-novo.
Soon after the cell theory came the “Theory of Evolution by Natural Selection” put forth by Charles Darwin and Russell Wallace in the year 1858. However, it took almost a century to appreciate the importance of this theory. Now, evolution is considered a core theme in biology. It connects all streams of biology and attempts to explain most biological phenomena in a logical way. So much so, the ideas from evolutionary biology have greatly aided in our understanding of animal behaviors (microbes to man, and, plants), survival strategies and so on. In addition, ideas from evolutionary biology have cogently contributed to the emergence of new branches like the Evolutionary Medicine, Evolutionary Psychiatry, Darwinian Agriculture, and Darwinian Fisheries.
Another major breakthrough in biology was elucidation of the principles of inheritance and as such the Discovery of Genetics by Gregor Johann Mendel (1865) who showed the existence of dominant and recessive traits (now called genes) that do not blend with each other. Since the late 20th century genetics has made advances by leaps and bounds leading to a new branch, termed, Epigenetics. Mendel is regarded as the father of Genetics.
The elucidation of the structure of DNA (1953) by James Watson, Francis Crick and Maurice Wilkins (who received Nobel Prize in 1962) and subsequent elucidation of principles of coding and transmission of genetic information by Har Gobind Khorana, Marshall W Nirenberg, and Robert W Holley (who received Nobel Prize in 1968) led to the birth of molecular biology. Knowledge of relationship between DNA, RNA and protein eventually led to developing techniques to amplify synthetic genes. Later, Kary Mullis developed technique of polymerase chain reaction (PCR) using a thermo-stable DNA polymerase for which he received the Nobel Prize (1993) in Chemistry.
In recent times, biological sciences have advanced enormously due to inputs from all other branches of sciences and keen interest in unravelling the secrets of life. The various breakthroughs in genetics and epigenetics, molecular biology, drug designing and biotechnology as well as in the emergence of novel frontier areas of research like Systems Biology, Computational Biology, Bioinformatics, In Silico Biology, Genome Editing and Synthetic Biology are the products of multidisciplinary researches. Modern Biology is thus very complex. Therefore, any deeper understanding of biology and its pursuit now requires sound knowledge of chemistry, physics, maths, statistics, computer science & several software, and use of artificial intelligence (AI). The AI has recently predicted the structures of nearly all known proteins (~350,000). Further, the DeepMind Company based in London using AI has predicted structures of nearly 200 million proteins- from bacteria to man (‘The Protein Universe’). Scientists are now able to edit genes to add or remove the desired ones.
Jennifer Doudna and Emmanuellle Charpetier who developed the CRISPR Cas-9 technology for gene editing received Nobel Prize in Chemistry (2020). Genome editing using CRISPR-Cas-9 technology enables removing / adding desired genes in organisms. It has given new hopes of improving the lives of man (ex: cure for cancer and other diseases and crop improvements etc.). In short, deeper insights in molecular biology, AI, computational biology and, development of diverse techniques and their applications have given unimaginable hopes in medicine, agriculture and other areas. Besides, these developments have marked not only the onset of a ‘Digital Era in Biology’ but also endorse the view that 21st Century belongs to Biology.
– Prof. S. K. Saidapur
Former VC, Karnatak University