Lobsters are terrifying immortal beings, sort of

Lobsters are immortal. Kind of. 

Along with tasting delicious when dipped in butter and garlic, lobsters have another great trait: They constantly produce telomerase. Instead of dying of old age, the crustaceans just get bigger and bigger, thanks to their molecular hack. 

Or as @JUNIUS_64 explained in her viral Twitter thread, they made “a deal with the devil for conditional immortality and it backfired on them.”

If the environmental conditions are welcoming enough, a lobster will just keep growing. The biggest lobster ever caught clocked in at about 44 pounds and was an estimated 140 years old. That lobster would have lived through the Civil War, a few industrial revolutions around the world, the Great Depression, both World Wars, and the first Woodstock. 

The secret to lobsters’ longevity, as @JUNIUS_64 explains, is something called a telomere. Telomeres are basically the aglets of chromosomes — they keep them from unraveling. Every time a human cell divides, our chromosomes lose some part of their telomeres. If telomeres reach a critical length, cells stop dividing. Since telomeres can’t be replicated, there’s a finite amount of times human cells can divide. When cells stop dividing, it’s basically time to die.

Humans gradually make less telomerase as we age. As @JUNIUS_64 beautifully put it, “our biology encodes death as an inevitability.”

But even lobsters, with their endless supply of telomerase, can’t avoid death forever. 

“Entropy always comes for its due, and that’s what even lobsters must accept,” @JUNIUS_64 explained.

How does death finally catch up? Molting. 

Lobsters — even though they don’t age — get bigger. And getting bigger involves growing out of their exoskeletons, which ends up being an extremely taxing, energy sapping activity. When they molt when they’re tiny, they’re especially vulnerable, but when they molt when they’re huge it can be dangerous.

“An ancient lobster colossus may not have as many predator concerns during a molt,” @JUNIUS_64 said, “but the energy costs are what kills.” 

At a certain point, moving out of their shells is just too much effort. (Honestly, same.) Their shells accumulate parasites and bacteria, and mega-lobsters essentially end up trapped in their own skeletons.

Twitter users were both fascinated and terrified by @JUNIUS_64’s thread.

So if you’ve heard of the giant lobster theory and were worried about massive crustaceans lurking at the bottom of the ocean, they’re not coming to get you. It’s probably just too much effort.