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Hans Spemann split a 2-cell newt embryo into two parts, resulting in the development of two complete larvae.
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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.
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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.
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First animal cloning: Robert Briggs and Thomas J. King cloned northern leopard frogs.
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Francis Crick and James Watson ,working at Cambridge's Cavendish Laboratory, discovered the structure of DNA.
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F.C. Steward grew a complete carrot plant from a fully differentiated carrot root cell.
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James Shapiero and Johnathan Beckwith announced that they had isolated the first gene.
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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.
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Steen Willadsen cloned a sheep from embryo cells, the first verified example of mammal cloning using the process of nuclear transfer.
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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.
