-
Period: to
Genetics Timeline
-
Walter Sutton
Pointed out the interrelationships between cytology and Mendelism, closing the gap between cell morphology and heredity. -
Nettie Stevens Edmund Wilson
Nettie Stevens Edmund Wilson and Independently described the behavior of sex chromosomes-XX determines female; XY determines male. -
Experiments
First experiments on quantitative traits in broad beans by Wilhelm Johanssen and in wheat by Herman Nilsson-Ehle. -
Erwin Chargaff
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
DNA is the molecule that mediates heredity, as shown in bacteriophage labeling experiments by Alfred Hershey and Martha Chase. -
Franklin and Wilkins
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. -
Meselson and Stahl
DNA replication is semi-conservative, as shown by Meselson and Stahl using equilibrium density gradient centrifugation. -
Smith and the enzzyme
The first restriction enzyme is purified by Hamilton Smith. -
First cloning of mammal
The first cloning of a mammal (Dolly the sheep) is performed by Ian Wilmut and colleagues, from the Roslin institute in Scotland. -
Still trouble
Controversies continue over human and animal cloning, research on stem cells, and genetic modification of crops.
