Editors note: This lecture is part of a series of lectures Prof. Kambadur Muralidhar gave at the University of Hyderabad in 2017, that he kindly shared with Club Sciwri. We will be publishing all the lectures, in parts, over the coming months.
The founding fathers of modern science especially Francis Bacon, René Descartes and Karl Popper emphasized the “Scientific method” which involves collection and interpretation of data in Natural Sciences. This is especially very important in Biology, which deals with the study of living organisms, which are characterized by a single most important feature i.e. diversity in structure and function. Following the scientific method requires that experiments are conducted under controlled conditions. Inductive reasoning was what the original scientific method suggested. This means that one should first collect the data and subsequently analyze them to observe ‘patterns’ or ‘paradigms’.
Darwin’s theory of organic evolution by Natural Selection is a classic example of the inductive reasoning approach.
Later, of course, science also approved hypothetico-deductive approach in doing science. Most of modern Biology is a combination of both the approaches. A null hypothesis drives and guides the collection of experimental data to disprove the hypothesis. However in both the approaches, reproducibility of observations/ experimental results is the key idea in scientific method. In fact Karl Popper goes to the extent of saying that “a non-falsifiable knowledge is not Science” which gives us the impression that while data is correct and absolute, interpretation can change and hence conclusions are not the absolute ‘Truth’. What exactly do scientists do during experimentation?
A cursory view reveals that scientists only ‘measure something’ during experimentation. There is exception to this truth. Physicists measure what they call ‘operational concepts’ (e.g. volume, height, velocity, electric voltage, temperature etc.). They then establish the relationships between two or three of these variables and express the truth in algebraic equations. These have become the Universal Laws of Mechanics, Thermodynamics, Electricity, Hydrodynamic properties etc. Chemists also measure, more often than not, concentration of solutions and transition state temperatures like melting point and boiling point. What do biologists measure?
Unfortunately for the first seventeen hundred years since Aristotle, Biologists did not measure anything. Hence biology was not a quantitative science for a long time!
Only during the seventeenth century and later, under the influence of René Descartes, biologists applied the concepts and techniques of Physics and Chemistry to analyze biological phenomena. They reduced biology to Physics and Chemistry. Biology therefore, also became a quantitative science. All the tools and techniques arise from Physics and Chemistry. There does not seem to be any purely biological technique! However, the end point of all measurement is a biological property and there exists ‘Biological Methods’ to achieve an end. We therefore realize that measurement is the foundation of all sciences. Science is akin to philosophy in seeking the ‘TRUTH’. Hence, the question arises as to how one should trust the experimental results or the products of measurement. Statisticians have developed certain criteria of reliability such as Precision, Accuracy, Sensitivity and Specificity. It is expected that biologists should design their experiments before executing them in order to get values for these criteria of reliability. Only then the conclusions drawn from the experiments would be valid.
Suggested Reading Material:
- A. Mead., Clark, SJ and Welham, SJ. (2010) Statistical Methods in Biology: Design and Analysis of Experiments and Regression, CRC Press.
Author
Prof. Kambadur Muralidhar is an Indian biologist, known for his work in biochemistry, endocrinology and reproductive biology. He taught at Delhi University for over thirty years, and was Head of its Department of Zoology. Currently, he is Jawaharlal Nehru Chair Professor, School of Life Sciences, University of Hyderabad. He is a Fellow of the Indian National Science Academy, the Indian Academy of Sciences, and the National Academy of Sciences, India. He is also highly regarded as a teacher and educator, and has contributed to biology education at both high school and college levels.
Editors
Roopsha Sengupta, PhD and Arunima Singh, PhD edited the article.
Roopsha did her PhD in the Institute of Molecular Pathology, Vienna and postdoctoral research at the University of Cambridge UK, specializing in the field of Epigenetics. Besides science and words, she enjoys spending time with children, doodling, and singing.
Arunima obtained her PhD from the University of Georgia, and is currently a postdoctoral researcher at the New York University. A computational structural biologist by training, she enjoys traveling, reading, and the process of mastering new cuisines in her spare time. Her motivation to move to New York was to be a part of this rich scientific, cultural, and social hub.
Artist
Ipsa designed the cover image. She is a post-doctoral fellow at Instem, Bangalore. She tries to communicate science through visual arts as a medium. Collecting graphic books, tree trash, and reading brain pickings is few of her favourites. Follow and purchase her artwork at Ipsawonders (Facebook, Twitter, and Instagram). She will be happy to hear praises and non-praises at ipsajain.31@gmail.com.
Other images in the blog courtesy Pixabay.
Blog design: Arunima Singh
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