IMPORTANT ACHIEVEMENTS MADE BY SCIENTISTS BIOLOGISTS UPTO 19TH CENTURY

Aristotle (384BC- 322BC) - A Greek philosopher and a student of Plato

 He classifi ed organisms on the basis of complexity in structure and function into a hierarchy,

Scala natura, the ladder of life

 He wrote Historia Animalium and De Generatione Animalium

 He is known as the father of Biology/ Zoology/ Embryology

Andreas Vesalius (1514-1564) – A Belgian scientist.

 He is known as the ‘Father of Anatomy’.

 He wrote De Humani Corporis Fabrica (the structure of human body)

William Harvey (1578 -1657) – A British Scientist.

 He discovered blood-circulation. His monograph was named ‘Anatomical Exercise on the

motion of the heart and blood’. He is known as the ‘Father of blood circulation’.

 He also studied reproduction and development in chick.

Robert Hooke (1635 – 1703 ) – A British Scientist.

 He fi rst coined the term cellulae (cell) in 1665 by observing slice of cork under self made

simple microscope.

 His book is named ‘Micrographia’

Antony Van Leeuwenhoek ( 1632-1723 ) – A Dutch cloth merchant .- turned into a scientist.

 He invented a simple microscope and studied living cells.

 He drew the diagram of bacteria and studied Euglena, sperms, blood corpuscles and

compound eyes of insects.

Carolus Linnaeus (1707-1778) - A Swedish Naturalist .

 He published ‘Species Plantarum’ (6000 species of plants) and Systema Naturae( 4000

species of animals ) .in 1758

 He also reported Binomial nomenclature, in Philosophia Botanica in 1751, for naming

plants and animals.

Georges Leopold Cuvier (1769-1832) - A French Palaeontologist .

 He rejected traditional Scala Naturae of Aristotle.

 He studied fossils and laid the foundation of Palaeontology. He is known to be the ‘Father

of Modern Palaeontology’.

 He also studied comparative anatomy.

Jean Baptiste Lamarck (1744 -1829) - A French Naturalist .

 He was the fi rst to discard the idea of fi xity of species.

 He is known to be the ‘Father of evolutionary theories’. He wrote Philosophie Zoologique

in 1809.

 He introduced the term ‘Biology’ (with Treviranus)

Robert Brown (1773-1858) -

 He discovered ‘Brownian movement’ in cytoplasm (1828).

 He also discovered ‘Nucleus’ in the cell.

Matthias Schleiden (1804-1881) - A German Botanist

 He Proposed cell theory in 1838 on the basis of his study on plant tissues.

Theodor Schwann (1810-1882) - A German Zoologist .

 He strengthened cell theory in 1839 by his study on animal tissues.

O. Hertwig (1875) -

 He studied fusion of nuclei during fertilization.

 He also proposed ‘protoplasmic theory’ to elaborate schultze’s hypothesis that ‘protoplasm

is the physical basis of life’.

 He also coined the term ‘cytology’.

Charles Robert Darwin (1809 - 1882 ) - A British Naturalist .

 His book ‘The origin of species by means of natural selection’ was published in 1859.

 He is called ‘Newton of Biology’.

 He proposed the ‘Theory of Pangenesis’ to explain inheritance in the book ‘On the variation

of animals and plants under domestication (1868)’

Rudolf C. Virchow (1858) -

 He proposed ‘Omnis cellula e cellulae’, i.e., New cells arise from pre-existing cells.

 He also suggested that disease is the pathological condition of cells.

Louis Pasteur (1822 - 1895 ) - A French Scientist.

 He proved that fermentation is caused by living organisms (Yeast and Bacteria).

 He established ‘Germ theory of diseases’.

 He discovered vaccine against Anthrax (caused by Bacillus anthracis in cattle ).

 He discarded ‘Spontaneous theory’ of origin of life.

 He also proposed Pasteurization for sterilization ( killing of germs )

Ernst Haeckel -

 He introduced 2-kingdoms, ‘Monera’ & ‘Protista’.

 He also coined and fully defi ned the term ‘Ecology’.

Gregor Johann Mendel (1822 - 1884 ) - An Austrian Monk

 He discovered principles of inheritance after his work on Pisum sativum, and published

them in 1866.

 Mendel is known to be the ‘Father of genetics’.

August Weismann (1834 - 1914 ) - A German Biologist

 He rejected Lamarck’s concept of ‘Inheritance of acquired characters’ and Darwin’s theory

of Pangenesis, with the discovery of ‘Theory of Germ plasm’ in 1892.