Excerpted from WHY WE DIE: The New Science of Aging and the Quest for Immortality by Venki Ramakrishnan with permission from William Morrow, an imprint of HarperCollins. Copyright © 2024 by Venki Ramakrishnan.
Lessons from a Lowly Worm
We all know families of long-lived individuals. But exactly how much do genes influence longevity? A study of 2,700 Danish twins suggested that the heritability of human longevity—a quantitative measure of how much differences in genes account for differences in their ages at death—was only about 25 percent. Further, these genetic factors were thought to be due to the sum of small effects from a large number of genes, and therefore difficult to pinpoint on the level of an individual gene. By the time that the Danish study was carried out in 1996, a lowly worm was already helping to overturn that idea.
That lowly worm was the soil nematode Caenorhabditis elegans, introduced into modern biology by Sydney Brenner, a giant of the field known for his caustic wit. Born and initially educated in South Africa, he spent much of his productive life in Cambridge, England, before he established labs all over the world from California to Singapore, leading some of us to remark that the sun never set on the Brenner Empire. He first became famous for having discovered mRNA. More generally, he worked closely with Francis Crick on the nature of the genetic code and how it was read to make proteins. Once he and Crick decided that they’d solved the fundamental problem of using genetic information to make proteins, Brenner turned his attention to investigating how a complex animal develops from a single cell, and how the brain and its nervous system work.
Brenner identified C. elegans as an ideal organism to study because it could be grown easily, had a relatively short generation time, and was transparent, so you could see the cells that made up the worm. He trained a number of scientists at the MRC Laboratory of…
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