In 1907-8, Thomas Hunt Morgan began to study Drosophila melanogaster in the laboratory. Morgan wasn’t the first to focus on the tiny fruitfly – in 1901 William E. Castle had begun breeding flies in Harvard.
Mendel’s laws had been rediscovered in 1903, but Morgan wasn’t interested in inheritance – indeed he was unconvinced about what was to be called “genetics”. Morgan wanted to look at evolution, by changing the flies’ environment and inducing what the scientist de Vries called “mutating periods”.
Throughout 1907 and 1908, hapless insects were therefore alternatively whizzed round in centrifuges, frozen, boiled, made to eat horrible food, and so on, in the vain hope that important mutational changes would arise. They never did. After three years, Morgan was ready to give the whole thing up as a bad job. Although Frank Lutz had found a wing mutant in 1908, nothing like a “mutating period” had been seen.
Then, in 1910, a series of mutations affecting different parts of the flies’ bodies began to appear – trident, olive, beaded and finally white. Using these and other mutants, in the next few years, Morgan and his students laid the foundations of modern genetics.
The flies finally had their say, however, in this YouTube song. One minor criticism, however – the song says flies don’t sleep. Oh yes, they do!
Thanks to Robert Myler for spotting this video.