Can your dna predict when you'll die?

What if your doctor could tell you how long your life would be — while you were still young? That's the possibility offered by a study released this week identifying a piece of DNA that

may serve as a measuring stick for longevity. Here, a brief guide to the research: WHAT PART OF THE DNA IS IT? The telomere — a protective cap on on the end of chromosomes, which are

thread-like strands of DNA. Essentially, a telomere serves a "similar purpose to the plastic caps at the end of shoelaces," says Loren Grush at _Fox News__,_ and keeps chromosomes

from unraveling. Researchers from the University of Glasgow in Scotland think that the length of a person's telomere, which wears down over time, could be used to estimate a

person's "expiration date" — or how long they can expect to live. SUBSCRIBE TO THE WEEK Escape your echo chamber. Get the facts behind the news, plus analysis from multiple

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to your inbox. From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox. HOW DID THEY TEST THIS? The team looked at 99 zebra

finches, measuring the telomeres found in the birds' red blood cells over the course of their lifespans, which was anywhere from just over 200 days to "old age" at nearly 9

years. Scientists discovered that measuring the length of the birds' telomeres 25 days after they hatched was a strong predictor for how long they would live; the birds with the longest

telomeres lived the longest natural lives. WHY IS THE TELOMERE A GOOD MEASURING STICK? Our cells are constantly dividing — "a necessary part of growth and the maintenance of our

bodies," says Wynne Parry at _Live Science_. And every time a cell makes a copy, it "misses the very tip of the telomere," which shrinks a little each time. Eventually our

cells stop dividing, and the "deterioration associated with aging" kicks in, making our bodies more susceptible to diseases like cancer. A free daily email with the biggest news

stories of the day – and the best features from TheWeek.com SO WHAT DOES THIS STUDY MEAN? It may offer scientists "a blueprint" to help them find ways to "better predict

longevity in humans," says _The State Column_. Though more studies need to be done — humans, of course, are not zebra finches — the findings could help us better predict our future

health and "usher in a new age of genetic research." _SOURCES: Fox News, Live Science, The State Column_