|Anne Robbs, Columnist|
They are usually associated with a life of gastronomic indulgence and heart-stopping excess. But away from the dinner table, lobsters may actually hold the secret to a long, healthy — and possibly even eternal — life. For this crustacean is one of a handful of bizarre animals that appear to defy the normal ageing process. While the passing years bring arthritis, muscle loss, memory problems and illness to humans, lobsters seem to be immune to the ravages of time. They can be injured, of course. They can pick up diseases. They can be caught and thrown into a pot, then smothered in béchamel sauce.
But rather than getting weaker and more vulnerable over the years, they become stronger and more fertile each time they shed their shells. The typical lobster weighs 1 to 2 lb. But in 2009, a Maine fisherman landed a colossus of 20 lb, which was estimated to be 140 years old. And that isn’t even the oldest lobster found so far. According to Guinness World Records, a 44 lb leviathan was caught in 1977, with claws powerful enough to snap a man’s arm.
The species belongs to an elite group that appears to be ‘biologically immortal’. Away from predators, injury or disease, these astonishing creatures’ cells don’t deteriorate with age. Scientists cannot be sure how long lobsters would live if they were simply left to exist — it wouldn’t be for centuries because of physical wear and tear, but it would certainly be for a lot longer than similar marine creatures.
Biological immortality isn’t just fascinating for wildlife experts. By studying the phenomena, scientists are shedding light on how age affects people and, as a result, developing new treatments for diseases such as cancer. It could even show us how to extend human life far beyond the standard three score years and ten. ‘The more scientists look, the more they find species that appear to be able to defy the ageing process,’ says Simon Watt, a biologist and TV presenter, who is speaking today at the British Science Festival in Newcastle. ‘These species of course still die. They get diseases, they are injured or hunted. But unlike humans, they don’t die as a result of their own metabolisms — there doesn’t seem to be a built-in life expectancy in their cells.’ There are many reasons why humans, along with most species on the planet, deteriorate with age. Mutations in DNA and the battering that our 100 trillion cells take every day contribute to the slow, inevitable decline. But scientists have discovered that our cells also have a built-in fixed lifespan — obsolescence if you like. Cells are constantly renewing and replacing themselves at a rate of millions every second. However, most human cells can only copy themselves 50 to 60 times before they die. The reason for programmed cell death lies in our chromosomes, the 46 strands of DNA found at the heart of almost every cell. The ends of every chromosome are protected with a chemical cap called a telomere. They act like the plastic tips on the end of shoelaces and stop the strands of DNA from fraying. But each time a human cell divides, these telomeres get shorter. Eventually — after 50 or so divisions — they are too short to protect the chromosomes, and the cell dies. It’s the same with almost all species — from frogs and goats to zebras and hummingbirds. But, amazingly, lobsters are different. They produce sufficient quantities of a substance called telomerase to renew these protective DNA caps and prevent cells dying. Lobsters aren’t the only creatures to have evolved biological immortality. One of the most incredible are the planarians, a group of flat worms.
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