EMERGENCE OF CONTEMPORARY BIOLOGY -

1.       Aristotle (384-322BC) - Greek

• Classified animal species and arranged them in hierarchies.
• Formulated 'Great chain of Being' or 'Scala Naturae' as chain of progressive change.
• Dealt with over 500 types of animals and dissected 50 of them.
• Studied developing embryo of chick and reported that sharks give birth to young ones but have no placenta like mammals, classified placental dolphins with mammals.
• Historia animalium (Natural history of animals)
• De Partibus animalium (Parts of animals) .
• De Generatione animalium (Reproduction of animals)
• He studied the development of chick embryo.
• Observed and reported vivipary in sharks (They do not develop placenta)

2.       Andreas Vesalius (1514-1564). Belgian; "Father of Anatomy"

Book : De Humani Corporis Fabrica (The structure of human body)

3.       William Harvey (1578-1657). British; demonstrated blood circulation pumped by heart.

Book: Anatomical Exercise on the Motion of the Heart and Blood. Also contributed-reproduction and embryonic development of chick.

4.       Robert Hooke (1635-1703) British;

Book: Micrographia. Coined the term 'cellulae'.

5.       Antony Von Leeuwenhoeck (1632-1723). Dutch cloth merchant turned scientist;

• Observed living cells with his own invented simple microscope. e.g. protozoans, human sperm, eggs, (and blood corpuscles of invertebrates, Hydra, about compound eyes of insects & many other animals structures.)
• First to draw a diagram of bacteria (1683).

6.       Carolus Linnaeus - (1707-1778) Swedish naturalist. Introduced Binomial nomenclature.

Book: Species Plantarum (1753) registers about 6000 species of plants.

Systema Naturae (1758) - recorded about 4000 species of animals.

7.       Georges Leopold Cuvier (1769-1832) French palaeontologist

• Rejected the traditional 'scala naturae' as a unifying concept of evolution.
• First to identify the fossils of extinct bird like reptile and laid the foundation of palaeontology.
• First to give concept of comparative anatomy of chordates.

8.       Jean Baptiste Lamarck (1744-1829) French naturalist; discarded the idea of fixity of species.

Book: Philosophie Zoologique (1809)

9.       Matthias Schleiden-(1804-1881) Cell theory - (1838) German Botanist

10.     Theodor Schwann-(1810-1882) Cell theory - (1839) German Zoologist

11.     Charles Robert Darwin -British naturalist (1809-1882).

Book: On the origin of species by natural selection:

12.     Louis Pasteur (1822-1895) french scientist.

• Refused the theory of spontaneous generation.
• Proved fermentation is caused by living organisms
• Gave Germ Theory of diseases, and developed scientific basis of immunity on cholera bacteria in chicken.
• Discovered vaccine against anthrax caused by Bacillus anthracis in cattle.
• His technique of killing germs (or sterlisation) Pasteurization.

13.     Gregor Johann Mendel (1822-1884) Austrian monk; discovered (1865) the Principles of inheritance which remained unknown to the world till 1900.

14.     August Weismann (1834-1914) - German biologist; gave theory of germplasm-(1892).