The clonal quaking aspen known as Pando is between 16,000 and 80,000 years old.
Not only is Pando, a massive quaking aspen that covers over 100 acres (40 hectares) in Utah, one of the largest known organisms on Earth, but scientists have also found that it is one of the oldest.
According to recent studies, the aspen (Populus tremuloides), which reproduces clonally by ramet-like shoots, is 16,000–80,000 years old. At 4,856 years old, the bristlecone pine Methuselah (Pinus longaeva) in eastern California is the oldest non-clonal organism on the planet. Based on the aspen’s genome’s rate of mutation over time, Pando’s age is estimated. Currently pending peer review, the paper was published on the preprint website bioRxiv.
According to Rozenn Pineau, a researcher at Utah State University and the study’s principal author, the estimate varies widely because aspen mutations are uncommon and it’s unclear how rapidly these genetic abnormalities accumulate in new shoots and stems, she told Live Science. The clone may have existed before the beginning of human migration out of Africa, however, as evidenced by the persistent presence of aspen pollen over 60,000 years found in a lakebed sampled close to Pando.
How did this organism manage to endure all of the changes in its surroundings throughout the years? Pineau spoken. It’s fascinating to consider these questions.
The largest tree in the world is the pando. Its name, which translates to “I spread” in Latin, is accurate: in the south-central Utah Fishlake National Forest, the organism has produced some 47,000 separate stems. Pando is the heaviest living thing on the planet because of its extensive underground root system, which connects all of these branches.
Paul Rogers, director of the research and conservation group Western Aspen Alliance, said there hasn’t been any solid science on Pando’s age up to this point. The current study did not include Rogers, who is an adjunct professor in the ecology department at Utah State University. “What they found here is a significant step forward,” he said in an interview with Live Science.
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Given that glaciers moved within a mile (1.6 km) of the current aspen growth location about 20,000 years ago, Rogers believes Pando may actually be closer to 16,000 years old than 80,000 years. According to him, aspens might have had a hard time surviving in that near-glacial setting. In contrast, he noted, the lakebed that Pineau and her colleagues studied for pollen may collect pollen from a wider area than Pando covers. Ancient DNA evidence would be necessary to demonstrate that the pollen originated, particularly in Pando.
Additionally, the study discovered that Pando appears to be skilled at controlling its genome. According to Pineau, mutations differed by location less than the researchers had anticipated. “You expect [stems] that are close in space to also be closer genetically,” she stated. However, until they focused on stems that were fewer than 49 feet (15 meters) apart, the researchers were unable to observe this link, indicating that Pando is often genetically identical.
“Mutations can locally accumulate,” said Pineau, “but they actually spread way less than we expected.”
Pineau and her team now intend to collaborate with Alyssa Phillips, a plant biology researcher at the University of California, Berkeley, to better understand the aspen’s mutation rate and further determine its age.
“The growth pattern of many different plants is the same,” Pineau stated. Because it’s large and ancient, this one has drawn a lot of attention, but it can teach us a lot about plant biology and resilience.
According to Rogers, Pando has been having trouble lately because of an overpopulation of grazers, primarily deer but also some cattle. The aspen has been gated off in some areas to protect it, and this tactic, combined with a few years of rain, appears to be helping the clone flourish.
As a researcher who has conducted extensive monitoring there, I am startled that when I visited earlier this fall, it appeared as though there was some kind of rebound taking place, Rogers said.