This is the first strong evidence showing that caloric restriction can significantly increase maximum lifespan in rodents (1935). This is a modified version of the classical tab, designed for easier readability. Whether or not you work on dietary restriction, what stands out to you in these results?

Since Weismann, breakthroughs in our understanding have largely come from the work of Haldane, Williams, and Hamilton. Yet, much remains to uncover. Yet here’s an old letter by Weismann I found in a German antique shop—one of my treasured discoveries.

What was Weismann thinking? He observed that smaller creatures often live shorter lives, while flying animals tend to live longer. Fascinated, he offered his own explanations and even predicted a limit to how many times somatic cells could divide (the Hayflick limit)🧵

However, the publication above is rather the essay itself. The first publication of his assay was published by the Society which hosted the event, in the Tageblatt der 54. Versammlung Deutscher Naturforscher und Ärzte🧵

Weismann wrote in German, which was a leading language in biological thought during the 1880s. His first exploration on aging, titled 'On the Duration of Life', was presented at the Assembly of German Naturalists/Physicians on September of 1881. I’m fortunate to own an original copy 🧵

Why do living things age? Have you heard of August Weismann? As someone passionate about the evolutionary biology of aging and the history of the field, I thought my first Bsky should highlight him—the first to propose Darwinian ideas on how aging might be shaped by natural selection🧵