1866 Mendel's paper is published: units of inheritance in pairs; dominance and recessiveness; equal segregation; independent assortment. These ideas are not recognized for 34 years.

1869 DNA (first called "nuclein") is identified by Friedrich Miescher as an acidic substance found in cell nuclei. The significance of DNA is not appreciated for over 70 years.

1900 Mendel's experiments from 1866 are "rediscovered" and confirmed by three separate researchers (one Dutch, one German, one Austrian). A British man (William Bateson) soon translates Mendel's paper into English and champions the study of heredity in England.

1902 A human disease is first attributed to genetic causes ("inborn errors of metabolism"). (Sir Archibald Garrod, alkaptonuria)

1902 The chromosome theory of heredity is proposed by Sutton. Boveri recognizes that individual chromosomes are different from one another, but he doesn't make a connection to Mendelian principles. Nevertheless, Boveri is given co-credit by friend E.B. Wilson (Sutton's supervisor) for proposing the chromosome theory of inheritance.

1905 The word "genetics" is coined by William Bateson.

1905 Some genes are linked and do not show independent assortment, as seen by Bateson and Punnett.

1903-9 First experiments on quantitative traits in broad beans by Wilhelm Johanssen and in wheat by Herman Nilsson-Ehle.

1910-11 The chromosome theory of heredity is confirmed in studies of fly eye color inheritance by T.H. Morgan and colleagues.

1913 First ever linkage map created by Columbia undergraduate Alfred Sturtevant (working with T.H. Morgan).

1910's-30's The eugenics movement is popular, fueling racist sentiment and leading to involuntary sterilization laws.

1925-27 H. Muller shows that X-rays induce mutations in a dose-dependent fashion.

1928 Some component of heat-killed virulent bacteria can "transform" a non-virulent

strain to become virulent, as shown by Fred Griffith. This sets the stage for work done in 1944.

1931 Genetic recombination is caused by a physical exchange of chromosomal pieces, as shown in corn by Harriet Creighton and Barbara McClintock.

1941 One gene encodes one protein, as described by Beadle and Tatum.

1944 DNA is the molecule that mediates heredity, as shown in Pneumococcus transformation experiments by Avery, MacLeod, and McCarty. Most people were skeptical of these findings until 1952.

1946 Genetic material can be transferred laterally between bacterial cells, as shown by Lederberg and Tatum.

1950 In DNA, there are equal amounts of A and T, and equal amounts of C and G, as shown by Erwin Chargaff. However, the A+T to C+G ratio can differ between organisms.

1952 DNA is the molecule that mediates heredity, as shown in bacteriophage labeling experiments by Alfred Hershey and Martha Chase. This confirmation of the 1944 results really convinced everyone.

1953 DNA is in the shape of a double helix with antiparallel nucleotide chains and specific base pairing. This was deduced by Watson and Crick, who used Rosalind Franklin's data provided by Maurice Wilkins.

1958 DNA replication is semi-conservative, as shown by Meselson and Stahl using equilibrium density gradient centrifugation.

1959 Messenger RNA is the intermediate between DNA and protein.

1966 The genetic code is cracked by a number of researchers (including Nirenberg, Matthaei, Leder, and Khorana) using RNA homopolymer and heteropolymer experiments as well as tRNA labeling experiments.

1970 The first restriction enzyme is purified by Hamilton Smith.

1972-73 Recombinant DNA is first constructed by Cohen and Boyer.

1977 DNA sequencing technology is developed by Fred Sanger.

1986 PCR is developed by Kary Mullis.

1990's Genome projects are begun. The yeast genome is complete in 1996, and the C. elegans genome is done in 1998.

1990's DNA microarrays are invented by Pat Brown and colleagues.

1990's DNA fingerprinting, gene therapy, and genetically modified foods come onto the scene.

1995 Automated sequencing technology allows genome projects to accelerate.

1996-7 The first cloning of a mammal (Dolly the sheep) is performed by Ian Wilmut and colleagues, from the Roslin institute in Scotland.

2000 The Drosophila genome is completed. The Arabidopsis genome is completed. The human genome is reported to be completed.

2001 The sequence of the human genome is released, and the "post-genomic era" officially begins.

2009 Controversies continue over human and animal cloning, research on stem cells, and genetic modification of crops.

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Selected books on historical figures/events in genetics



Overviews/chronologies Mendel's Legacy: The Origins of Classical Genetics by Elof Axel Carlson History of Genetics: From Prehistoric Times to the Rediscovery of Mendel's Laws by Hans Stubbe (MIT press, out of print) A History of Genetics by Alfred Sturtevant The Eighth Day of Creation by Horace Freeland Judson (focus on molecular biology) The Century of the Gene by Evelyn Fox Keller Cracking the Genome : Inside the Race to Unlock Human DNA by Kevin Davies Operators and Promoters Examinations of particular people or experiments The Monk in the Garden by Robin Marantz Henig (Mendel) Lords of the Fly by Robert E. Kohler (sociology of Drosophila genetics) The Transforming Principle by Maclyn McCarty Meselson, Stahl, and the Replication of DNA by Frederic Lawrence Holmes We Can Sleep Later: Alfred Hershey and the Origins of Molecular Biology edited by Franlkin W. Stahl In the Name of Eugenics: Genetics and the Uses of Human Heredity by Daniel J. Kevles The Double Helix by James Watson Rosalind Franklin and DNA by Anne Sayre Rosalind Franklin: the Dark Lady of DNA by Brenda Maddox A Feeling for the Organism by Evelyn Fox Keller (Barbara McClintock) The Tangled Field: Barbara McClintock's Search for the Patterns of Genetic Control by Nathaniel Comfort (Barbara McClintock) Time, Love, Memory by Jonathan Weiner (Seymour Benzer and Drosophila behavioral genetics)







© Copyright 2002-2009 Department of Biology, Davidson College, Davidson NC 28035

last modified August 27, 2009 by K. Hales