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Cloning Newts
Hans Spemann split a 2-cell newt embryo into two parts, resulting in the development of two complete larvae. -
Disproving Weismann's Theory
German embryologist Hans Spemann split a 2-celled salamander embryo and each cell grew to adulthood, providing proof that early embryo cells carry necessary genetic information. This finally disproved Weismann's 1885 theory that the amount of genetic information in cells decreases with each division. -
Successful Nuclear Transfer
Hans Spemann published the results of his 1928 primitive nuclear transfer experiments involving salamander embryos in the book "Embryonic Development and Induction." Spemann argued the next step for research should be the cloning organisms by extracting the nucleus of a differentiated cell and putting it into an enucleated egg. -
First Cloning
First animal cloning: Robert Briggs and Thomas J. King cloned northern leopard frogs. -
DNA Structure Discovered
Francis Crick and James Watson ,working at Cambridge's Cavendish Laboratory, discovered the structure of DNA. -
Cloning Carrota
F.C. Steward grew a complete carrot plant from a fully differentiated carrot root cell. -
First Gene Discovered
James Shapiero and Johnathan Beckwith announced that they had isolated the first gene. -
Gene Splicing
Stanley Cohen and Herbert Boyer created the first recombinant DNA organism using recombinant DNA techniques pioneered by Paul Berg. Also known as gene splicing, this technique that allows scientists to manipulate the DNA of an organism - the basis of genetic engineering. -
Sheep Cloning
Steen Willadsen cloned a sheep from embryo cells, the first verified example of mammal cloning using the process of nuclear transfer. -
Cloning Sheep with Human DNA
Ian Wilmut and Keith Campbell, the scientists who created Dolly, also created Polly, a Poll Dorset lamb cloned from skin cells grown in a lab and genetically altered to contain a human gene.
