History of Genetics

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History of Genetics
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The Beginning
1859 Darwin publishes the Origin of the
Species Stating that members Of a population
that are Better adapted live longer And pass on
their traits. Nothing has been proposed About
how these traits are Passed on.
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1866 Gregor Mendels Publishes

• Law of Inheritance
• Based upon experiments started in 1857 on pea
  plants
• Ignored until 1900, well after his death in 1884

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1969 DNA nuclein first recognized

• Identified by Freidrich Miescher and an acidic
  substance found in the nucleus.
• Not appreciated for 70 years

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1900 Mendel Rediscovered

• Confirmed by 3 different researchers
• Translated by William Bateson into English the
  the study of heredity begins

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1902 lst human disease attributed to genetic
causes.

• Sir Archibald Garrod identified alkaptonuria

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1902 Chromosomes come in pairs

• American biologist Walter Sutton demonstrated
  that chromosomes came in pairs and were alike in
  structure

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1905 Genetics is used for first time

• Coined by William Bateson in a personal letter to
  Alan Sedgwick on April 18, 1905

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1905 Some genes are linked

• They dont show independent assortment as
  described by Bateson and Punnett.
• Punnett developed the Punnett square to look at
  probability in genetic choices.

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1910-11 Chromosome Theory of heredity is confirmed

• T.H. Morgans experiments fruit fly eye color
  confirm this.

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1913 1st Linkage Map

• Created by Columbia undergraduate Alfred
  Sturtevant working ith T.H. Morgan
• Linking traits to gene on chromosomes.

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1910-1930 Eugenics

• Social philosophy which advocates the improvement
  of human hereditary traits through various forms
  of intervention

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Eugenics used for Sterilization Laws

• 1907 First law in Connecticut
• 1914 Harry Laughlin published the Model Eugenical
  Sterilization Law
• Sterilize socially inadequate people in
  institutions

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Sterilization Laws Purpose

• Clearly, these laws were meant to keep
  "defective" individuals from reproducing amongst
  themselves and, thus, reduce the burden of
  "social dependents" who had to be supported in
  state institutions.
• Less clear, perhaps, was the intent to prevent
  mildly retarded people from reproducing with
  normal people, and thus, contaminate good genetic
  stock.

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Sterilization Purpose

• This fear was generated by Henry H. Goddard's
  study of Martin Kallikak (1912), a normal man who
  sired a "defective" line after having an illicit
  affair with an attractive, but "feebleminded"
  girl. This was analogous to the fear of a mixed
  race person who might "pass for White.

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Sterilization

• In Skinner vs. Oklahoma (1942), the Supreme Court
  struck down a law allowing the involuntary
  sterilization of criminals. However, the Court
  never prohibited states from sterilizing
  non-criminals, despite later scholarship showing
  the falsity of eugenic "evidence" used in Buck
  vs. Bell.
• Sterilization of the allegedly mentally ill
  continued into the 1970s in several states, by
  which time about 60,000 Americans had been
  involuntarily sterilized

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Task

• Go to Eugenics archive at
• http//www.eugenicsarchive.org/eugenics/list3.pl
• Investigate one of the aspects of Eugenics. Write
  a paragraph outlining what you learned and a
  paragraph on what you think of this use of
  genetics.

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1928 Heat killed virulent bacteria can
transform non-virulent bacteria.

• There must be a genetic transfer.

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1931 Genetic recombination

• Caused by a physical exchange of chromosome
  pieces.
• Harriet Creighton Barbara McClintock in corn

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1941 One gene encodes one protein (1958 Nobel
prize)

• Beadle Tatum

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1944 DNA mediates heredity

• Avery, MacLeod McCarty
• Most didnt believe until 1952

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1950 Chemical Components of DNA

• Amounts are equal of A T C G
• By Erwin Chargaff
• Austrian who emigrated to US in 1935

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1953 DNA Double Helix

• Watson, Crick, Wilkins Rosalind Franklin

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1955 human chromosomes46

• Joe Hin Tjio

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1959 mRNA intermediate between DNA protein

• Sydney Brenner
• Matthew Meselson
• Francois Jacob

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1966 Each aa coded for by codon

• Marshall Nierenberg
• H. Gobind Khorana

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1977 DNA sequencing Technology

• Fred Sanger

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1978 RFLPS discovered

• Restriction Fragment Length Polymorphisms
• Found throughout the genome are a ! Markers in
  genetic studies
• David Botstein

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1983 PCR developed

• Polymerase chain reaction making lots of copies
  of DNA sequences
• Kary Mullis

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1983 Gene for Human disease is mapped -
Huntingtons

• Gene responsible for the disease is on the short
  arm of chromosome 4

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1984 DNA Fingerprinting

• Sir Alec Jeffreys

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1989 Natl. Center for Human Genome Research
created

• 3 Billion US effort headed by James Watson

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1990 The Human Genome Project

• International effort to sequence all DNA and map
  all the genes in humans is launched.

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1992 Map genetic markers on 23 chromosomes

• Daniel Cohen

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1994 High-density Map of Human Genome published

• 6000 markers identifying genes for Bipolar
  disorder, hearing loss, dyslexia, thyroid cancer,
  sudden death syndrome, and dwarfism

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1995 Full genome on bacteria

• Hemophilus influenzae
• Bakers yeast
• 12 million pairs of DNA

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1999 SNP consortium

• Single nucleotide polymorphisms (SNPs) -the most
  common form of genetic variation.

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2000 Rough Draft of Human Genome is Completed

• Goals to discover all 30,000-40,000 human genes
  and make them accessible for further study

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2001 Private Company clones human embryos

• Advanced Cell Technology - private U.S. company
  announced it cloned embryos