Griffith demonstrates (Griffith's experiment) that living cells can be transformed via a transforming principle, later discovered to be DNA (1928). Karl von Frisch decodes the waggle dance honey bees use to communicate the location of flowers (1940). George Wells Beadle and Edward Lawrie Tatum moot the "one gene-one enzyme hypothesis" based on induced mutations in bread mold Neurospora crassa (1941). Luria–Delbrück experiment demonstrates that in bacteria, beneficial mutations arise in the absence of selection, rather than being a response to selection (1943). Barbara McClintock breeds maize plants for color, which leads to the discovery of transposable elements or jumping genes (1944). Linus Pauling and colleagues show in "Sickle Cell Anemia, a Molecular Disease" that a human genetic disease, sickle cell anemia, is caused by a molecular change in a specific protein, hemoglobin (1949). Hershey–Chase experiment (by Alfred Hershey and Martha Chase) uses bacteriophage to prove that DNA is the hereditary material (1952). Meselson–Stahl experiment proves that DNA replication is semiconservative (1958). Crick, Brenner et al. experiment using frameshift mutations to support the triplet nature of the genetic code (1961). Nirenberg and Matthaei experiment demonstrating in vitro protein synthesis using synthetic RNA as to substitute for messenger RNA (1961). John Gurdon clones an animal, a frog tadpole, from an egg cell using the nucleus from an intestinal cell (1962). Roger W. Sperry shows the potential independence of the two sides of the human brain using split-brain patients (1962–1965). Nirenberg and Leder experiment, binding tRNA to ribosomes with synthetic RNA to decipher the genetic code (1964). Demonstration of the role of reverse transcriptases in tumor viruses, independently by Howard Temin and David Baltimore, 1970. Herbert Boyer and Stanley Cohen selectively clone genes in bacteria, using bacterial plasmids cut by specific endonucleases (1975). Mary-Dell Chilton shows that crown gall tumors of plants are caused by the transfer of a small piece of DNA from the bacterium Agrobacterium tumefaciens into the host plant, where it becomes part of its genome (1977). Napoli, Lemieux and Jorgensen discover the principle of RNA interference (1990). Chemistry Blaise Pascal carries a barometer up a church tower and a mountain to determine that atmospheric pressure is due to a column of air (1648). Robert Boyle uses an air pump to determine the inverse relationship between the pressure and volume of a gas. This relationship came to be known as Boyle's law (1660–1662). Joseph Priestley suspends a bowl of water