The Violinist's Thumb: And Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code by Sam Kean Read Free Book Online Page B

commute two hundred miles to Cornell University to finish a master’s degree. But no matter how frazzled he got, Muller used his one free day, Thursday, to drop in on Morgan and the fly boys and bandy about ideas on genetics. Intellectually nimble, Muller starred in these bull sessions, and Morgan granted him a desk in the fly room after he graduated from Cornell in 1912. The problem was, Morgan declined to pay Muller, so Muller’s schedule didn’t let up. He soon had a mental breakdown.
    From then on, and for decades afterward, Muller seethed over his status in the fly room. He seethed that Morgan openly favored the bourgeois Sturtevant and shunted menial tasks like preparing bananas onto the blue-collar, proletariat Bridges. He seethed that both Bridges and Sturtevant got paid to experiment on his, Muller’s, ideas, while he scrambled around the five boroughs for pocket change. He seethed that Morgan treated the fly room like a clubhouse and sometimes made Muller’s friends work down the hall. Muller seethed above all that Morgan was oblivious to his contributions. This was partly because Muller proved slow in doing the thing Morgan most valued—actually carrying out the clever experiments he (Muller) dreamed up. Indeed, Muller probably couldn’t have found a worse mentor than Morgan. For all his socialist leanings, Muller got pretty attached to his own intellectual property, and felt the free andcommunal nature of the fly room both exploited and ignored his talent. Nor was Muller exactly up for Mr. Congeniality. He harped on Morgan, Bridges, and Sturtevant with tactless criticism, and got almost personally offended by anything but pristine logic. Morgan’s breezy dismissal of evolution by natural selection especially irked Muller, who considered it the foundation of biology.
    Despite the personality clashes he caused, Muller pushed the fly group to greater work. In fact, while Morgan contributed little to the emerging theory of inheritance after 1911, Muller, Bridges, and Sturtevant kept making fundamental discoveries. Unfortunately, it’s hard to sort out nowadays who discovered what, and not just because of the constant idea swapping. Morgan and Muller often scribbled thoughts down on unorganized scraps, and Morgan purged his file cabinet every five years, perhaps out of necessity in his cramped lab. Muller hoarded documents, but many years later, yet another colleague he’d managed to alienate threw out Muller’s files while Muller was working abroad. Morgan also (like Mendel’s fellow friars) destroyed Bridges’s files when the free lover died of heart problems in 1938. Turns out Bridges was a bedpost notcher, and when Morgan found a detailed catalog of fornication, he thought it prudent to burn all the papers and protect everyone in genetics.
    But historians can assign credit for some things. All the fly boys helped determine which clusters of traits got inherited together. More important, they discovered that four distinct clusters existed in flies—exactly the number of chromosome pairs. This was a huge boost for chromosome theory because it showed that every chromosome harbored multiple genes.
    Sturtevant built on this notion of gene and chromosome linkage. Morgan had guessed that genes separating 2 percent of the time must sit closer together on chromosomes than genes separating 4 percent of the time. Ruminating one evening,Sturtevant realized he could translate those percentages into actual distances. Specifically, genes separating 2 percent of the time must sit twice as close together as the other pair; similar logic held for other percent linkages. Sturtevant blew off his undergraduate homework that night, and by dawn this nineteen-year-old had sketched the first map of a chromosome. When Muller saw the map, he “literally jumped with excitement”—then pointed out ways to improve it.
    Bridges discovered “nondisjunction”—the occasional failure of chromosomes to separate cleanly after