Longevity

Science

10 rabbit holes · 7 people exploring

Common starting questions

• Why do cells stop dividing?
• How do you figure out the age of a shark?
• Is cellular reprogramming a realistic way to reverse aging?

Rabbit holes

1. axolotls regrow limbs, hearts, parts of their brain

   Noor Rahman · 5 sources

2. The jellyfish that can reverse its own life cycle

   When stressed it turns back into a polyp and starts over. Not immortal in the 'can't die' sense, it still gets eaten constantly, but still.

   Priya Natarajan · 5 sources

3. how do we know the oldest people were really that old?

   Calment's 122 years is the record. In 2018 two Russian researchers argued her daughter had taken over her identity decades earlier. Most gerontologists who examined the evidence disagree, but it sent me into how ages get validated at all.

   Milan Popović · 6 sources

4. cells can only divide about 50 times, except the ones that never stop

   Noor Rahman · 7 sources

5. why don't whales get cancer more often?

   Inês Carvalho · 4 sources

6. naked mole-rats barely age

   Live 30+ years (a mouse lives ~3), rarely get cancer, and don't seem to have mortality that rises with age. Also they have a queen. Also they're cold-blooded-ish. Also they don't feel some kinds of pain.

   Grace Whitfield · 5 sources

7. the young blood thing

   Old mice joined to young ones show improvements in muscle, liver and brain markers. That spawned startups selling young plasma infusions, until the FDA put out a warning about them in 2019.

   Grace Whitfield · 5 sources

8. Greenland sharks were aged using the lenses of their eyes

   Nils Eriksson · 5 sources

9. can you reset a cell's age? (Yamanaka factors)

   Four transcription factors can turn an adult cell back into a stem cell and wipe most of its age markers along the way. The longevity idea is to do it only partially, so cells get 'younger' without forgetting what kind of cell they are.

   Grace Whitfield · 6 sources

10. rapamycin was found in soil from Easter Island

    A Canadian expedition in the 1960s collected soil on Rapa Nui, and a bacterium in it made the molecule. It became a transplant drug, then a lab favorite in aging research.

    Frida Nyström · 6 sources