units of inheritance in pairs; dominance and recessiveness; equal segregation; independent assortment.
Study of Heredity in England
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
Some genes are linked
Some genes are linked and do not show independent assortment, as seen by Bateson and Punnett.
First Experiments on Quantitative Traits
First experiments on quantitative traits in broad beans by Wilhelm Johanssen and in wheat by Herman Nilsson-Ehle
The chromosome theory of heredity is confirmed in studies of fly eye color inheritance by T.H. Morgan and colleagues.
Genetic recombination is caused by a physical exchange of chromosomal pieces, as shown in corn by Harriet Creighton and Barbara McClintock.
Gene encodes protein
One gene encodes one protein, as described by Beadle and Tatum.
Genetic material can be transferred laterally between bacterial cells, as shown by Lederberg and Tatum
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.
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
Discovery that messenger RNA is the intermediate between DNA and protein.
Advancements in DNA
DNA fingerprinting, gene therapy, and genetically modified foods come onto the scene
The first cloning of a mammal (Dolly the sheep) is performed by Ian Wilmut and colleagues, from the Roslin institute in Scotland.
The sequence of the human genome is released, and the "post-genomic era" officially begins
Controversies continue over human and animal cloning, research on stem cells, and genetic modification of crops.