The Gene: An Intimate History - Siddhartha Mukherjee Page 0,25

is likely that he sent one to Darwin, but there is no record of Darwin’s having actually read it.

What followed, as one geneticist wrote, was “one of the strangest silences in the history of biology.” The paper was cited only four times between 1866 and 1900—virtually disappearing from scientific literature. Between 1890 and 1900, even as questions and concerns about human heredity and its manipulation became central to policy makers in America and Europe, Mendel’s name and his work were lost to the world. The study that founded modern biology was buried in the pages of an obscure journal of an obscure scientific society, read mostly by plant breeders in a declining Central European town.

On New Year’s Eve in 1866, Mendel wrote to the Swiss plant physiologist Carl von Nägeli in Munich, enclosing a description of his experiments. Nägeli replied two months later—already signaling distance with his tardiness—sending a courteous but icy note. A botanist of some repute, Nägeli did not think much of Mendel or his work. Nägeli had an instinctual distrust of amateur scientists and scribbled a puzzlingly derogatory note next to the first letter: “only empirical . . . cannot be proved rational”—as if experimentally deduced laws were worse than those created de novo by human “reason.”

Mendel pressed on, with further letters. Nägeli was the scientific colleague whose respect Mendel most sought—and his notes to him took an almost ardent, desperate turn. “I knew that the results I obtained were not easily compatible with our contemporary science,” Mendel wrote, and “an isolated experiment might be doubly dangerous.” Nägeli remained cautious and dismissive, often curt. The possibility that Mendel had deduced a fundamental natural rule—a dangerous law—by tabulating pea hybrids seemed absurd and far-fetched to Nägeli. If Mendel believed in the priesthood, then he should stick to it; Nägeli believed in the priesthood of science.

Nägeli was studying another plant—the yellow-flowering hawkweed—and he urged Mendel to try to reproduce his findings on hawkweed as well. It was a catastrophically wrong choice. Mendel had chosen peas after deep consideration: the plants reproduced sexually, produced clearly identifiable variant traits, and could be cross-pollinated with some care. Hawkweeds—unknown to Mendel and Nägeli—could reproduce asexually (i.e., without pollen and eggs). They were virtually impossible to cross-pollinate and rarely generated hybrids. Predictably, the results were a mess. Mendel tried to make sense of the hawkweed hybrids (which were not hybrids at all), but he couldn’t decipher any of the patterns that he had observed in the peas. Between 1867 and 1871, he pushed himself even harder, growing thousands of hawkweeds in another patch of garden, emasculating the flowers with the same forceps, and dusting pollen with the same paintbrush. His letters to Nägeli grew increasingly despondent. Nägeli replied occasionally, but the letters were infrequent and patronizing. He could hardly be bothered with the progressively lunatic ramblings of a self-taught monk in Brno.

In November 1873, Mendel wrote his last letter to Nägeli. He had been unable to complete the experiments, he reported remorsefully. He had been promoted to the position of abbot of the monastery in Brno, and his administrative responsibilities were now making it impossible for him to continue any plant studies. “I feel truly unhappy that I have to neglect my plants . . . so completely,” Mendel wrote. Science was pushed to the wayside. Taxes piled up at the monastery. New prelates had to be appointed. Bill by bill, and letter by letter, his scientific imagination was slowly choked by administrative work.

Mendel wrote only one monumental paper on pea hybrids. His health declined in the 1880s, and he gradually restricted his work—all except his beloved gardening. On January 6, 1884, Mendel died of kidney failure in Brno, his feet swollen with fluids. The local newspaper wrote an obituary, but made no mention of his experimental studies. Perhaps more fitting was a short note from one of the younger monks in the monastery: “Gentle, free-handed, and kindly . . . Flowers he loved.”

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I. Several statisticians have examined Mendel’s original data and accused him of faking the data. Mendel’s ratios and numbers were not just accurate; they were too perfect. It was as if he had encountered no statistical or natural error in his experiments—an impossible situation. In retrospect, it is unlikely that Mendel actively faked his studies. More likely, he constructed a hypothesis from his earliest experiments, then used the later experiments to validate his hypothesis: he stopped counting and tabulating the peas once they had conformed to the expected values