The quest to decelerate, or even partially undo, the ravages of aging has led researchers down some improbable avenues, none more unlikely than the sedentary sea squirt.
These unprepossessing filter feeders, edible in several cultures and permanently fastened to submerged rock, have yielded a compound with unexpectedly potent biological effects.
When this substance was administered to aged mice, the animals staged a measurable recovery across faculties that ordinarily erode with time, most notably memory and muscular strength.
Rather than simply slowing the downward trajectory, the intervention appeared to reverse several established hallmarks of senescence.
Findings of this calibre bolster an increasingly influential hypothesis: that ageing is not a rigid, one-way descent but a pliable process amenable to modulation.
The researchers, however, are conspicuously disciplined in their interpretation, resisting the temptation to overstate.
This remains resolutely preclinical work, executed in rodents under controlled conditions and nowhere near validated in people.
The chasm between a promising result in mice and a safe, effective human therapy is wide, and bridging it will demand years of rigorous, painstaking trials.