this presentation is also about history of genetics but before mendels work. different contribution of different scientists are discussed in this presentation.

2. HISTORY OF GENETICS
(POST-MENDELIAN)
BY
MUHAMMAD NASEER

3. CHARLES DARWIN (1809-1882)
• He Established that all species of life have descended over time
from common ancestry
• He Proposed the scientific theory that this branching pattern of
evolution resulted from a process that he called natural
selection.
• He published his theory with compelling evidence for evolution
in his 1859 book ”On the Origin of Species”.

4. GREGOR MENDEL
• He is considered as “The father of Genetics”.
• He Published the results of his investigations of the
inheritance of "factors" in pea plants in 1866.
• He proposed two laws of Inheritance
• Law of Segregation
• Law of Independent Assortment

5. HUGO DE VRIES, CARL CORRENS, ERICH VON
• Three scientists who rediscovered
Mendel's laws in 1900. They were all
working independently on different
plant hybrids, and came to the same
conclusions about inheritance as
Mendel.
• Hugo de Vries adopts the term mutation in
1901.
Hugo de Vries Carl Correns Erich von Tschermak

6. WALTER SUTTON AND THEODOR BOVERI
• In 1902 he Pointed out the
interrelationships between cytology
and Mendelism, closing the gap
between cell morphology and heredity.
• WS Sutton and Theodor Boveri (studying sea
urchins) independently propose the
chromosome theory of heredity
W.S Sutton

7. WILLIAM BATESON
• In 1905 He coined the terms
genetics, allele, homozygous,
heterozygous

8. THOMAS HUNT MORGAN
• In 1910 he discovered that how genes are
transmitted by chromosomes;
• He work on sex linkage in Drosophila

9. FREDRIECH GRIFFITH
• In 1928 he discovered transformation in bacteria.
• he work on 2 strains of Streptococcus Pneumoniae.
• One is called S-strain which was virulent and cause
pneumonia in Mice.
• While another is R-stain which was not virulent and can not
cause pneumonia in mice.

10. ROSALIND FRANKLIN
• 1st study the chromosomes in 1951.
• Show by X-ray crystallography that DNA
exists as two strands wound together in
a spiral or helical shape

11. MARTHA CHASE AND ALFRED HERSHEY
• In 1952 they Used phages in
which the protein was labeled
with 35S and the DNA with 32P
for the final proof that DNA is
the molecule of heredity.

12. FRANCIS CRICK AND JAMES WATSON
• In 1953 they Solved the
three-dimensional
structure of the DNA
molecule.
• DNA is double helical.
Francis Crick James Watson

13. JEO HIN TIJO AND ALBERT LEVAN
• In 1956 they showed that the
diploid chromosome number
for humans is 46
Jeo Hin Tijo Albert levan

14. ARTHUR KORNBERG
• In 1958 he Purified DNA polymerase I from
E. coli, the first enzyme that made DNA in a
test tube.
• his work in DNA synthesis led to creating
recombinant DNA and genetic engineering.

15. H. GOBIND KHORANA AND MARSHALL NIRENBERG
• In 1966 they Led teams that cracked
the genetic code- that triplet mRNA
codons specify each of the twenty
amino acids.
H. Gobind Khorana Marshall Nirenberg

16. STANLEY COHEN, HERBERT BOYER AND PAUL BERG
• In 1972 they invent Recombinant
DNA Technology.
Stanley Cohen Herbert Boyer Paul berg

17. JOSEPH SAMBROOK
• In 1973 he Led the team at Cold Spring
Harbor Laboratory that refined DNA
electrophoresis by using agarose gel and
staining with ethidium bromide.

18. THE END

19. THANKS