Posts Tagged ‘life extension’
“The secret of longevity is to keep breathing”*…
Shelly Fan, with news of a new study that proports to gauge the limits of longevity…
In 1997, Jeanne Calment passed away at the age of 122 and a half. The longest living human documented to date, she pushed the boundary of what was previously considered the maximum human lifespan.
Meanwhile, in 2023, Guinness World Records recognized Pat the mouse as the oldest mouse alive at a little over nine and a half years old—just a sliver in years compared to humans.
When it comes to lifespan, we mammals have an astonishing range. The common shrew lives less than two years; bowhead whales thrive for at least 211 years. Why the discrepancy?
Part of it, according to Dr. Steve Horvath and colleagues at the University of California, Los Angeles, comes down to epigenetics: the chemical tags attached to DNA that flip genes on or off. The type and position of these tags shift through major life events—puberty, aging—and even with dietary changes.
Unlike genetics, the study of genes coded in DNA, epigenetics better captures the “here and now” of gene expression as we go through life. Previously, Horvath and others have tapped epigenetics to develop “aging clocks” that predict a person’s biological age—that is, how old your body is biologically, rather than the number of candles on your birthday cake.
In a new study in Science Advances, Horvath’s team expanded their epigenetic clocks to predict three life-changing traits: gestation time—how long the next generation fully grows in the womb—puberty, and maximal lifespan.
“Many have suggested that epigenetic mechanisms play a role in determining lifespan,” wrote the team in the paper.
Taking advantage of data from the Mammalian Methylation Consortium, they analyzed one type of epigenetic modification in over 15,000 tissue samples across 348 mammals and developed multiple epigenetic predictors for the three life-history traits across species.
The predictors were reliable. When challenged with lifestyle and demographic factors often associated with changing epigenetic markers—for example, weight, race, and biological sex—they retained their accuracy. Surprisingly, even notable methods for extending lifespan in the lab, for example, caloric restriction, had little effect on the clock’s measures.
“This [epigenetic] signature may be an intrinsic property of each species that is difficult to change,” the team wrote…
More at: “New ‘Aging Clock’ Predicts the Maximum Lifespan of 348 Mammals Including Humans,” from @ShellyFan in @singularityu.
The underlying paper, “Epigenetic predictors of species maximum life span and other life-history traits in mammals,” is here.
* Sophie Tucker
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As we age, we might send quixotic birthday greetings to Roy Walford; he was born on this date in 1924. A professor of pathology (also at UCLA), he was a pioneer in arguing for calorie restriction as a way of extending life (and a crew member of Biosphere 2.)
Walford died in 2004 at the age of 79 (though in fairness, his demise was a result of Lou Gehrig’s disease, which a could have been the result of low oxygen, high nitrous oxide levels in the Biosphere, causing the loss of brain cells).
“To be ignorant of what occurred before you were born is to remain always a child”*…
There’s history… and then there’s deep history. C. Patrick Doncaster, a professor of ecology at Southampton University has created “Timeline of the human Condition- Milestones in Evolution and History.” Starting with the Big Bang (13.8 billion years ago) it marks significant events in Earth’s development, the evolution of life, and the development of human culture (science/technology, economics, politics, and art) all the way up to 2021.
It concludes with a trio of handy analogies…
Following the big bang 13.8 billion years ago, time passed two-thirds of the way to the present before the formation of the Sun 4.57 billion years ago. Rescaled to a calendar year, starting with the big bang at 00:00:00 on 1 January, the Sun forms on 1 September, the Earth on 2 September, earliest signs of life appear on 13 September, earliest true mammals on 26 December, and humans just 2 hours before year’s end. For a year that starts with the earliest true mammals, the dinosaurs go extinct on 17 August, earliest primates appear on 9 September, and humans at dawn of 25 December. For a year that starts with the earliest humans, our own species appears on 19 November, the first built constructions on 8 December, and agricultural farming begins at midday on 29 December.
“Timeline of the Human Condition- Milestones in Evolution and History.” (via @Recomendo6)
See also: “How We Make Sense of Time.”
* Marcus Tullius Cicero
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As we prize perspective, we might spare a thought for James Hiram Bedford; he died on this date in 1967. A psychologist who wrote several books on occupational counseling, he is best remembered as the first person whose body was cryopreserved after legal death. He remains preserved at the Alcor Life Extension Foundation in Arizona.
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