List of Scientists and their Contributions

Dear students, here I have tried to compile all the scientists and their contributions given in the NCERT Class-XII Biology Textbook.

If you have any suggestions or additions, please do put in the comments section.

Happy Studying :)

Scientist	Contribution
Gregor Johann Mendel	a) Father of genetics b) Conducted experiments for the first time to understand the pattern of inheritance and variation.
Reginald C Punnett	Punnett square
Galton	Polygenic inheritance
De vries,Correns,VonTschermark	Independently rediscovered Mendel's work.
Walter Sutton and Theodore Boveri	Chromosomal theory of inheritance
Thomas Hunt Morgan(and his colleagues)	a) Experimental verification of chromosomal theory of inheritance. b) Linkage and Recombination.
Alferd Sturtvant	Chromosomes maps or linkage maps
Henking	X-Body (Chromosome)
Friederich Miesher	Nuclein
Maurice Wilikins and Rasalind Franklin	X-ray diffraction data leading to the proposal of structure of DNA
James Waston and Francis Crick	Proposed the structure of double helix model for the DNA; Semi conservative mode of DNA replication.
Erwin charagaff	Chargaff Rule: A+T/G+C=1
Francis Crick	Central dogma in molecular Biology; tRNA as adapter molecule
Frederick Grieffith	Transforming principle; carried out a series of experiments with streptococcus pneumonia.
Oswald Avery, Colin Macleod and Maclyin Mc carty	Determined the biochemical nature of transforming principle.
Alferd Hershy and Martha Chase	The unequivocal proof that DNA is the genetic material
Matthew Meselon and Franklin Stahl	Experimented to prove DNA replicates semi-conservatively
George Gamaw	Genetic codon should be made up of 3 nucleotides
Hargovind Khuarana	Developed a chemical method for the synthesis of RNA molecule with defined base combination
Marshall Nirenberg	Put forward a cell free system for protein synthesis that help in deciphering the code
Severo Ochoa	Showed the polynucleotide phosphate also helped in polymerizing RNA with define sequence in a template in depend manners
Francois Jacob and Jacque Monad	Transitionally regulated system - lac operon
Frederick Sanger	a) developed method for determination of amino acid sequences in protein. b) Developed a principle the automated DNA sequences worked on.
A.I Oparin and John Haldane	Proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that formation of life was preceded by chemical evolution.
Louis Pasteur	Disapproved Theory of Spontaneous Generation. Experimentally demonstrated that life comes only from pre-existing life.
S L Miller	Miller’s experiment on the origin of life. He revealed that life originated from the nonliving components.
Charles Darwin	Father of Evolution Concept of natural selection Concept of reproductive fitness Darwin finches - adaptive radiation
Alfred Wallace	Worked in Malay Archipelago and had a similar opinion as that of Mendel on the concept of reproductive fitness and natural selection.
Lamark	Evolution due to use and disuse of organs
Thomas Mathus	Proposed Malthusian theory of population - this theory states that population growth will always tend to out run the food supply. This theory is thought to influence Darwin.
William Harvey	Discovered of blood circulation
Hugo deVries	Developed mutation theory - saltation
G. H. Hardy and Wilhelm Weinberg	Hardy-Weinberg principle - genetic equilibrium in a population.
Norman E Borlaug	He improved methods of cultivation and developed a robust strain of wheat. Semi-dwarf wheat.
Alexander Fleming	Discovery of first antibiotics- Penicillin
Ernest Chain and Howard Florey	Established the full potential of penicillin as an antibiotics.
Stanley Cohen and Herbert Boyer	Construction of the first recombinant DNA
Gause	Provided competitive Exclusion principle: two closely related species competing for the same resources cannot coexist indefinitely and the competitively inferior one will be eliminated eventually
Mac Arthur	Resource partitioning: Showed that five closely related species of warblers living on the same tree were able to avoid competition and co-exist due to behavioral differences in their foraging activities
Edward Wilson	Coined biodiversity to describe the combined diversity at all the levels of biological organization
Robert Constanza	He used to put price tags on nature's life support services
Robert May	Made a more conservative and scientifically sound estimate which places the global species diversity at about 7 million.
Alexander von Humboldt	Observed that within a region species richness increased with increasing explored area, but only upto a limit
David Tilman	His long-term ecosystem experiments states that plots with more species showed less year-to-year variation in total biomass
Paul Ehrlich	Provided the ‘rivet popper hypothesis’ to show how quality of life is affected with reduction in organism.