A grove of over 40,000 trees in rural Utah, collectively known as Pando, is not just the largest single organism on Earth, but it may also be the oldest. This massive clone of trembling aspens, all genetically identical and descended from a single seedling, covers an area of 106 acres and weighs nearly 13 million pounds. While Pando’s sheer size has made it a subject of fascination, recent research has raised the intriguing possibility that it has been alive for tens of thousands of years.
A recent study, which has yet to undergo peer review, estimates Pando’s age to be between 16,000 and 80,000 years. This wide range, though uncertain, places the grove's origins somewhere between the retreat of the glaciers from Manhattan and the time when Neanderthals vanished from the fossil record. The research team, led by Rozenn Pineau of the University of Chicago, used genetic analysis to estimate the age of Pando. By sequencing DNA from over 500 samples of leaves, bark, and roots, they calculated the grove’s age based on the rate of somatic mutations—random changes to DNA that accumulate as an organism ages.
The study uncovered that although Pando’s trees are physically close to one another, their genetic relationships are less tightly linked than expected. This suggests that some unknown mechanism is limiting the spread of mutations across the grove. Interestingly, despite Pando’s vast size, the genetic makeup of the organism remains surprisingly uniform. This genetic stability may help explain how it has survived for so long, even though cloning species typically face challenges related to genetic diversity.
Unfortunately, Pando is currently in decline due to threats from deer, bark beetles, and disease. Conservation efforts are underway to promote new growth and preserve this remarkable organism. As researchers continue to refine their understanding of Pando’s age and evolutionary trajectory, one thing is clear: the ancient grove of Pando offers a unique window into the resilience of life and the evolutionary power of clonal reproduction.
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