Till about mid-nineteenth century, biology was not seen as a science subject. It meant history; to be precise, ‘Natural History’. Accordingly, documenting animal or plant varieties (especially for their medicinal properties), classifying them (more exactly after 1735 thanks to Carl Linnaeus), describing their occurrence, morphology, anatomy, and housing them in ‘Natural History Museums’ were the major obsessions of natural scientists.  Few experiments were conducted on animals to gain insights in human physiology with medicine in mind. All other areas like: animal development, role of eggs and sperms, fertilization, tissue differentiation or principles of inheritance and so on remained black boxes till late 19th century. Likewise, existence of ‘microbes’ or ‘microbial world’ remained unknown till microscopes with good resolution became available. Study of microbes thus began in the 17th century. Today, ‘Microbiology’ is an important branch of Biology and Medicine.

Progress in biology is closely linked to development of tools and techniques needed to probe interior of cells, tissues, organs etc. Therefore, biological sciences lagged physical sciences and became their younger sibling. Biology made path-breaking progresses in 19th century with three major milestones in quick succession to each other. They are: 1) conception of ‘Cell Theory’ (based on the works of Robert Hooke, Anton Leeuwenhoek, T. Schwann and M.J. Schleiden, 1839 and others), 2) ‘Theory of Evolution’ (Charles Darwin and Alfred Russel Wallace, 1858), and 3) discovery of ‘Principles of Inheritance’ (Gregor Mendel, 1855). They constitute three major pillars of biology. The fourth major milestone (pillar) of biology was deciphering of 1) structure of DNA (Watson and Crick, 1953) and, 2) principles of coding and molecular mechanisms of transfer of genetic information by Har Gobind Khorana, M. W. Nirenberg and R. W. Holley, hundred years after Mendel’s fundamental studies of inheritance -between 1960-1970.  Significance of the four major pillars is described below. The ‘Cell Theory’ is a generalized concept and includes the idea that ‘cell’ is a basic unit of life, and new cells arise through division of preexisting cells (Virchow, 1865).  Further, all cells are surrounded by a plasma membrane which is structurally a fluid mosaic structure (S. J. Singer and G. L Nicolson in 1972). The fluid mosaic model enabled a thorough understanding of how cell membranes perform diverse functions (e.g. synthesis, degradation, transport of substances across, regulation of substances entering or leaving cells, recognition of antigens etc.). Various cell organelle (e.g. mitochondria, Golgi apparatus, endoplasmic reticulum etc.) are also membranous structures. Cell biology is now out-and-out molecular biology.

Darwin’s ‘Theory of Evolution’ significance of which was recognized hundred years after it was proposed is the second major pillar in biology.  It led to undertaking numerous comparative studies (e.g. fossils, anatomy, physiology, organs, physiological systems, life history strategies etc.) across animal / plant kingdoms. By the turn of 20^th century, evolutionary biology made rapid strides and connected different branches of biology.  Thus, most biological phenomena (normal or bizarre) are now better understood using ideas of evolutionary biology.  ‘Evolution’ is now a core theme in biology. Furthermore, it has contributed to its own new branches such as ‘Darwinian Medicine’ or ‘Evolutionary Medicine’, ‘Darwinian Fisheries’, ‘Darwinian Agriculture’ and ‘Evolutionary Psychiatry’ with practical applications.

Third milestone in biology was founded by Gregor Mendel who elucidated the principles of heredity. He is regarded as the father of ‘Genetics’.  He discovered that parental traits (e.g. color, height etc.) are due to discrete ‘factors’ (now known as ‘genes’) do not blend on mixing in the offspring. Such factors may be dominant or recessive in nature. In offsprings, dominant traits only are expressed. However, when an offspring receives recessive factors from both parents the trait is expressed. Thus, in the absence of (gene for) dominant factor recessive factors are expressed. Over the years, classical genetics has now turned in to molecular genetics.

The fourth milestone or pillar of biology is unraveling structure of DNA and composition of genes which helped reveal molecular mechanisms of heredity, protein synthesis, gene regulation of development and differentiation, cell memory and so on which paved way for unthinkable opportunities: genetic manipulations (gene cloning) for in vitro production of desired proteins (e.g. human insulin) using microbes, blood clotting factors and vaccines through pharma agriculture, genetically modified (GM) animal/plant varieties with preferred traits (e.g. high yielding, drought resistant etc.), production of designer babies by gene editing (e.g. AIDS resistant babies) to name a few. Importantly, advances in biological sciences also led to ‘white’, ‘blue’ and ‘green’ revolutions and mitigated food shortages faced in the bygone century. Now India exports surplus food grains, vegetables, and fruits to other countries.

Thus, progresses made in biological sciences are phenomenal. So much so, the 21^st century has heralded digital biology. With the help of digital techniques new domains like, genomics, proteomics, bioinformatics, and systems biology have now emerged. The latter deals with cells with a systems perspective to study the sub systems of a cell and molecular interactions within it. Using artificial intelligence (AI) structures of ~200 million of 350,000 million proteins (from bacteria to man) have been predicted and thereby erected a ‘Protein Universe’ (DeepMind Company, London). Such studies produce gigantic amount of data. Consequently, in silico or ‘computational biology’ has now emerged. It helps to manage huge data (Exabytes) that is otherwise impossible to handle. 

Further, encouraged by deep understanding, availability of tool and techniques scientists have now created a novel domain of biology called ‘Synthetic Biology’ which attempts to design and fabricate biological components to perform specific functions with applications in agriculture and medicine.  It is a mix of basic biology, biophysics, biochemistry, bioinformatics, systems biology, and bioengineering.  Scope of biology is thus progressively becoming broad, highly complex. These developments depict true nature of biology; that is interdisciplinary specialty. Finally, biological sciences have changed greatly in the past five decades from classical to molecular and now digital.

The transformations outlined above present four significant messages. 1) Growth, expansion, accomplishments, and future foreseeable opportunities in biological sciences unequivocally plead for changing our approaches towards both teaching and research. They call for interdisciplinary approach in teaching and multidisciplinary approach in research. 2) Inclusion of basics of physical sciences, math, and statistics is now inevitable. Such integrated approaches alone can help craft discoveries and innovations. 3) Despite huge progresses in biology there remain many secrets of life waiting to be resolved (e.g. human mind, spirituality, consciousness, ethics, morality, etc.).  Resolution of such abstract domain calls for involvement of brilliant minds of both scientists and philosophers. 4) Finally, application of ideas from evolutionary biology on how human behaviors evolve will go a long way in evolving strategies for regulation of a desirable social order.