Where does "father of genetics" Gregor Mendel fit in a post-genomic world? Gregory Radick has written an excellent reset.
IN 1865, an Austrian monk called Gregor Mendel, working to understand hybridisation, uncovered exquisitely simple and reliable patterns of inheritance in varieties of garden pea. In 1900, the patterns he described were rediscovered and thought by some to reveal the existence of hereditary “particles” – particles that we now call genes. With this, Mendel became “the father” of genetics.
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| A painting showing Gregor Mendel at work in his garden, where he studied garden peas Bettmann Archive/Getty Images |
Well, of course there is more to the story, as we discover in Disputed Inheritance: The battle over Mendel and the future of biology, an ambitious work by science historian Gregory Radick. In paying attention to today’s sophisticated ideas about genetics, Radick poses a deceptively simple question: why, he asks, knowing what we do now, do we still bother with Mendel? Why, when we explain genetics, do we reach for experiments conducted by a man with no interest in heritability, never mind evolution? And one, he argues, whose conclusions on heritability (in as much as he ever made any) were spectacularly contradicted in experiments with pea hybrids by Thomas Laxton, Charles Darwin’s favourite botanist, in 1866.
The evidence against Mendelian genetics began accumulating almost immediately after its rediscovery. Modern genetics is arguably not Mendelian, it is molecular, informed by the likes of microbiology, biochemistry, X-ray crystallography and, later, a host of data-rich sequencing technologies.
Radick underlines this shift by citing a 2014 paper by evolution theorist Evelyn Fox Keller. She writes that the genome is reactive, “a device for regulating the production of specific proteins in response to the constantly changing signals it receives from its environment”, rather than the pre-genomic picture of a static collection of genes leading inexorably to inherited traits.
The point isn’t that Mendel was wrong. That would be like saying Isaac Newton was wrong for not coming up with general relativity. The point is we may have no real need to think in Mendelian terms at all. Couching almost all of modern genetics as an exception to Mendel’s specious “rules” is to constantly explain everything backwards.
Radick outlines how we got here, and what we can do. The seed of trouble was sown in the battle between two zoologists, William Bateson at the University of Cambridge, who made it his mission to reshape biology in the image of Mendel’s experiments, and Raphael Weldon at the University of Oxford, who saw that Mendel had removed from his experiments as many sources of variability as he could.
Real peas aren’t always just yellow or green, or just round or wrinkled, and Weldon argued that variability shouldn’t be idealised away. “It seems to me that every character is at once inherited and acquired,” wrote Weldon. He was right: the difficulty was what to do with that insight. “It is easy to say Mendelism does not happen,” he remarked to his friend Karl Pearson in 1903, “but what the deuce does happen is harder every day!”
Weldon needed (and pursued) an alternative theory of heredity, but his manuscript setting it out was unfinished by his death in 1906.
Radick champions the underdog Weldon over the victorious Bateson. Whether his account smacks of special pleading depends on the reader’s education and interests. Temperatures in this field run high: less than a century ago, geneticists in the Soviet Union were ruined – some even died – defending Mendel’s idea, insufficient as that idea can seem to us now.
This isn’t the first attempt to lay history’s ghosts to rest and reset our ideas about genetics. That said, I can’t think of one that is better argued, more fair-minded or more enjoyable.
Simon Ings is a writer based in London
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