An Early Experiment Hinting at DNA

Anomaly (2) was observed by Fred Griffith, decades before DNA and the genetic code. He found that if you inject a heat-treated, dead, virulent species of bacteria (pneumococcus S) into a rat previously infected with a nonvirulent species (pneumococcus R), then species R became transformed into species S, thereby killing the rat. About fifteen years later, Oswald Avery found that you can even do this in a test tube; dead S would transform live R into live S if the two were simply incubated together; moreover, the change was heritable. Even the juice from S did the trick, leading Avery to suspect that a chemical substance in the juice—DNA—might be the carrier of heredity. Others replicated this. It was almost like saying, “Put a dead lion and eleven pigs into a room and a dozen live lions emerge,” yet the discovery was largely ignored for years. Until Watson and Crick deciphered the mechanism of transformation.


V. S. Ramachandran on a fascinating experiment involving combining dead bacteria with live to produce new bacteria.

Folksonomies: history genetics dna

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Gene (0.686029): dbpedia | freebase
Organism (0.528604): dbpedia | freebase
Biology (0.522029): dbpedia | freebase | opencyc
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 This Will Make You Smarter
Books, Brochures, and Chapters>Book:  Brockman , John (2012-02-14), This Will Make You Smarter, HarperCollins, Retrieved on 2013-12-19
  • Source Material []
  • Folksonomies: science