This collection of more than 40,000 trees in rural Utah is the largest single living organism in the world, all descended from a single sapling. But that’s not all. According to a team of researchers, this grove (collectively known as Pando) may also be home to the world’s oldest living organisms.
Although Pando is made up of more than 40,000 individual trees, it is a single organism born from a single seed. But the exact time when that seed germinated remains up in the air. Pando is between 16,000 and 80,000 years old, according to a team of researchers who recently estimated the creature’s age. In other words, between the time the glaciers retreated from Manhattan and the last time Comet Tochinshan-ATLAS crossed Earth’s skies, seedlings in what would become Utah began to form pandos. . The team’s research on Pando has not yet been peer-reviewed; hosted On the preprint server bioRxiv.
The groves that make up Pando are the largest and densest living organisms ever known, weighing approximately 13 million pounds (5.9 million kilograms) and covering an area of 106 acres (43 hectares). is. According to the US Forest Service. A recent study suggests that Pando may have already been 40,000 years old, when Neanderthals disappeared from the fossil record about 40,000 years ago.
“We studied a very iconic creature whose size made us wonder about its evolution in time and space,” said Rosen, a researcher at the University of Chicago and lead author of the study.・Pino said in an email to Gizmodo. “We expected that nearby trees in space would be more closely related genetically. We found that to be the case, but only to the extent that we It was much lower than I expected.”
To estimate the clone’s age, the research team sequenced more than 500 samples from Pando and nearby areas. The researchers sampled a variety of tree tissues, including leaves, roots, and bark, and separated somatic mutations from germline mutations in the clones. Germline mutations occur in the germ cells of the parents and are inherited, while somatic mutations are changes in the DNA that occur after a cell is conceived. These random mutations occur throughout an organism’s life, and the researchers were able to calculate the approximate age of the grove from the rate of these mutations.
“Clonally replicating organisms can also achieve very long lifespans, making somatic mutation an important mechanism for producing genetic variation in Darwinian evolution by natural selection,” the researchers wrote in their paper. states. “However, little is known about mutation rates and evolutionary trajectories within long-lived organisms.”
The researchers created a phylogenetic model that explains how mutations were introduced into Pando clones over time and revealed the age range of the ancient grove. The researchers determined Pando’s age to be between 16,000 and 80,000 years old. This is certainly a wide range, but it is supported by the presence of aspen pollen in sediment samples taken from nearby Fish Lake.
“Despite that root spread is spatially restricted, only a weak positive correlation between genetic distance and spatial distance was observed, which could influence the accumulation and spread of mutations between units. “This suggests the existence of a protective mechanism,” the research team said in their paper. In other words, despite the limited spread of Pando’s roots, its genetic makeup is surprisingly uniform. The researchers suggest that some unknown process seems to limit mutations from accumulating throughout the grove.
“To take into account the uncertainty in the step of calling mutations, we considered three scenarios, which is why this age range is so wide,” Pinault added. “There’s a good chance we’ll arrive at a narrower window. In fact, our colleagues at the University of California, Berkeley are currently working on obtaining higher-resolution genetic data to narrow this window.”
According to the Forest ServicePandos are in decline due to browsing by ungulates, including deer, and attack by bark beetles and disease. Foresters are working to encourage new trees to sprout in Pando to prevent this ancient wonder of life from going the way of the dodo. Or a woolly rhinoceros. Or a mammoth. Or other species that existed parallel to Pando but were unable to survive beyond it.
