Biology Series-1 (English) GREAT BIOLOGISTS of THE WORLD Collected & Edited by Assisted by Prof. Sunil D. Purohit Dr. Renu Tripathi Published by Society for Promotion of Science Education and Research 11-12, New Ganpati Nagar-A, Bohra Ganesh Marg, Udaipur (Rajasthan) N ISSIO D MI N AN VIS IO Promong Excellence in Science Educaon and Research Through Sciencezaon (Science S e n s i z a o n ) , S u p p o r v e Teaching, Conceptual and Pracce Learning and Training as a part of Academic Social Responsibility Program (ASRP) SPSER SPSER Published by Society for Promotion of Science Education and Research 11-12, New Ganpati Nagar-A, Bohra Ganesh Marg, Udaipur-313001 (Rajasthan) e-mail : [email protected] First Edition : 2019 Printed by : Apex Printing House Contribution Amount: Rs. 10.00 only Great Biologists of the World 40 GREAT BIOLOGISTS OF THE WORLD Collected and Edited by Professor Sunil Dutta Purohit Former Head, Department of Botany Mohanlal Sukhadia University, Udaipur (Raj.) Assisted by Dr. Renu Tripathi (Sukhwal) New Middle East International School, Riyadh Kingdom of Saudi Arabia Financial Support Dr. Renu-Sunil Dutt Tripathi Riyadh, Kingdom of Saudi Arabia Published by Society for Promotion of Science Education and Research 11-12, New Ganpati Nagar-A, Bohra Ganesh Marg, Udaipur (Rajasthan) Great Biologists of the World 41 CONTENTS 1. Antonie van Leeuwenhoek 1 2. Robert Hooke 4 3. Carolus Linnaeus 8 4. Edward Jenner 12 5. Charles Darwin 16 6. Louis Pasteur 20 7. Gregor Mendel 24 8. Robert Koch 28 9. Alexander Fleming 32 10. Max Delbruck 35 1 Antonie van Leeuwenhoek Father of Microbiology Antonie van Leeuwenhoek is known as Father of Microbiology. Leeuwenhoek for the first time demonstrated the presence of microorganisms in the environment which could not be seen with the naked eyes.With the help of microscopes created by him, he observed in different water samples, the presence of tiny motile objects which he designated them as ‘Animalcules’. These tiny objects turned out to be Bacteria as we know them today. Leeuwenhoek with this discovery opened up altogether a new area of scientific investigation which had great impact on human civilization. Antonie van Leeuwenhoek was born on October 24, 1632 in a picturesque old town of Delft in Holland. His father was a basket maker and mother, the daughter of a brewer. Leeuwenhoek earned his livelihood as a cloth merchant and it was common for him to use small lenses to check the quality of clothes that he used to sell as draper. Rare sense of his curiosity in observing other objects through his lenses opened up a new area of scientific enquiry for him. He spent lot of his spare time constructing simple microscopes composed of double convex lenses held between two silver plates. Leeuwenhoek not only recorded every minute detail of his observations but also sent detailed letters to Great Biologists of the World 2 the Royal Society of London, describing his observations. There were a record 372 letters in all, written by Leeuwenhoek throughout his long life of ninety years. The last letter of Leeuwenhoek was mailed by her daughter after his death along with a cabinet containing 26 of his finest and most beloved silver microscopes. It was clear from his descriptions that he saw both bacteria and protozoa. He is believed to have created about 400 microscopes, of which, 7 are still present in the Natural History Museum of London. Discovery of microorganisms by Leeuwenhoek ended the long held myth that life spontaneously appeared from the non- living organisms. This further solved the mystery and confirmed that spoilage of the food, making of wine and turning milk into cheese involved microorganisms. It is interesting to note that Leeuwenhoek had a very little knowledge on how to present his scientific observations. This was reflected in the series of his letters written to the Royal Society of London. The letters were written in colloquial Dutch and often began with some simple talk about life in Delft, or his personal habits, his pet dog, or his business upturns and downturns, and then moved on to describing an amazing variety of microscopic observations. His scientific observations were made with painstaking care and exactness and this approach made him the most respected microscopist in the world. Leeuwenhoek had said “My work, which I have done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men”. The Royal Society of London, in the year 1680 conferred on him the membership of the society which was a rare honor for a person who did not have a formal scientific training! He became famous and a stream of visitors started pouring in his home, Great Biologists of the World 3 some time leading to loss of his privacy and causing discomfiture to him. One day Peter the Great, the Emperor of Russia called on him to see his instruments. He had to carry his instruments to a Yacht by which the Emperor had come through a canal, and he did not want to attract crowd by visiting the home of Leeuwenhoek. Leeuwenhoek was very secretive in nature and was not willing to share the art of making microscopes to anyone during his lifetime. He passed away in the year 1723. Leeuwenhoek will be remembered for astounding and detailed nature of his discoveries which revolutionized our lives in more than several ways. Great Biologists of the World 4 2 Robert Hooke A Natural Philosopher who Discovered Cell Robert Hooke was a noted natural scientist who made variety of observations on natural world. He is known as ‘Renaissance Man’ of 17th Century England for his work in sciences which covered areas such as Philosophy, Architecture, Chemistry, Astronomy, Physics and Biology including construction of scientific instruments. His most notable discovery was about cells, a term which he coined for microscopic honeycomb cavities in sliced cork. He was a true polymath who studied comets, the motion of light, the rotation of Jupiter, gravity, human memories and the properties of air. He invented or improved all the five meteorological instruments such as Barometer, Thermometer, Hydroscope, Rain Gauge and Wind Gauge. He developed and printed a form to record weather data. Hooke explained the basis of the phenomenon of elasticity known as Hooke’s Law. Robert Hooke was born on July 18, 1635 at Freshwater on the Isle of Wight, Hampshire in England. His father John Hooke was a priest of England and the Curate of Freshwater’s Church of All Saints. His mother Cecily Glyles was second wife of his father. Hooke was educated mostly at home during his early years due to ill health. He was a quick learner and had Great Biologists of the World 5 great interest in painting and making of mechanical toys and models. Unfortunately, his father passed away in 1748 when Hooke was only 13 years old. His father left a meager 40 Pound Sterling (INR 3500) as inheritance. With this amount in hand he went to London and was first apprenticed to painter Peter Lely and Samuel Cowper and proved fairly good at art, but he left because the fumes of the paint adversely affected his health. He enrolled at the Westminster School in London, where he received a solid academic education including Latin, Greek and Hebrew and also gained training as an instrument maker. After graduating from Westminster School, Robert Hooke took admission in Christ Church College of the University of Oxford. He studied experimental science here. In 1655, at 20 years of age, Robert Hooke became an assistant to a well known chemist Robert Boyle. He was working with Boyle when he discovered Boyle’s Law and helped him in construction and operation of Boyle’s Air-Pump. He worked with Boyle for seven consecutive years till 1762, after which he was appointed as the curator of experiments for the Royal Society of London. He held this position for 40 years. Initially the Royal Society of London was not in a position to pay anything to him for the Curator’s position. Hooke eventually got paid for the curatorship when he was appointed as a professor of Geometry at Gresham College in London in the year 1665. While he was already working with Boyle, he also came in contact with an eminent architect Christopher Wren, natural philosopher John Wilkins and Isaac Newton who were also associated with the society. Hooke became Fellow of the Society in the year 1663. In 1665, he published his famous book ‘Micrographia’ (meaning- Small drawings) in which he documented the observations he had made through various lenses of a microscope Great Biologists of the World 6 in a period of about nine months. It featured many drawings, such as that of a detailed flea and a slice of cork observed through the microscope. Hooke was the first person to use the word ‘Cell’ to identify microscopic structures when he was describing cork. The word ‘Cell’ for these structures came to his mind due to its resemblance to cells inhabited by Christian Monks in a Monastery. It is considered to be one of the most important scientific books ever written, which became a bestseller during that time. In the year 1670s he postulated that gravitational pull applies to all celestial bodies. He stated that it decreases with distance and in its absence the body would tend to move in a straight line. He could not give any evidence for this hypothesis. In the year 1678 publication of Hooke’s ‘Lectures of Spring’ shared his theory of elasticity which later on came to be known as Hooke’s Law.