Daily Archives: 21 March 2014

March 21, 1925 (a Saturday)

On this date, Tennessee Governor Peay signed into law the Butler Act, “prohibiting the teaching of the Evolution Theory” in all public schools and universities and making it unlawful in public schools “to teach any theory that denies the story of the Divine Creation of man as taught in the Bible, and to teach instead that man has descended from a lower order of animals.” This set the stage for the Scopes’ “Monkey Trial” in Dayton, Tennessee during the subsequent summer.

The author of the law, a Tennessee farmer named John Washington Butler, had introduced the bill into the state House of Representatives on January 25, 1925. Ironically, he later was reported to have said, “No, I didn’t know anything about evolution when I introduced it. I’d read in the papers that boys and girls were coming home from school and telling their fathers and mothers that the Bible was all nonsense.” After reading copies of William Jennings Bryan’s lecture “Is the Bible True?” as well as Charles Darwin’s The Origin of Species and The Descent of Man, Butler decided evolution was dangerous. During the trial, Butler told reporters, “I never had any idea my bill would make a fuss. I just thought it would become a law, and that everybody would abide by it and that we wouldn’t hear any more of evolution in Tennessee.”


March 21, 1932 (a Monday)

On this date, the American molecular biologist Walter Gilbert was born. In 1980, he was awarded the Nobel Prize in Chemistry with Frederick Sanger and Paul Berg. Gilbert and Sanger were recognized for their pioneering work in devising methods for determining the sequence of nucleotides in a nucleic acid.

A Maxam-Gilbert sequencing gel.

A Maxam-Gilbert sequencing gel.

In a 1986 article (Nature 319: 618), Gilbert was the first scientist to use the term “RNA world” to refer to a possible stage in the origin of life on Earth (although the hypothetical possibility of an RNA world had already been suggested by others before him):

The first stage of [chemical] evolution proceeds, then, by RNA molecules performing the catalytic activities necessary to assemble themselves from a nucleotide soup. The RNA molecules evolve in self-replicating patterns, using recombination and mutation to explore new niches. … they then develop an entire range of enzymic activities. At the next stage, RNA molecules began to synthesize proteins, first by developing RNA adaptor molecules that can bind activated amino acids and then by arranging them according to an RNA template using other RNA molecules such as the RNA core of the ribosome. This process would make the first proteins, which would simply be better enzymes than their RNA counterparts. … These protein enzymes are … built up of mini-elements of structure.

Finally, DNA appeared on the scene, the ultimate holder of information copied from the genetic RNA molecules by reverse transcription. … RNA is then relegated to the intermediate role it has today—no longer the center of the stage, displaced by DNA and the more effective protein enzymes.

The possibility of an RNA world in the origin of life had been supported by the discovery by Thomas Cech in 1982 of the existence of naturally-occurring ribozymes.