One of the great mysteries of plant biology is a seemingly immortal tree called the Trembling Aspen (Populus tremuloides), which reproduces by growing clones from its root system. A new study suggests that the trees live for 20,000 years.
Because these aspens live for so long, nobody had been able to determine exactly how many years the trees survive before they start to show signs of aging. So University of British Columbia biologist Dilara Ally determined to find out. She defined "aging" as "diminishing fertility," and she measured fertility simply by examining how much pollen was being released by the male trees (she didn't include female trees in the study). She also figured out ages of the clones via "molecular clock" - looking at how many mutations they had in their genomes, since each successive generation of clones gets more and more mutated.
According to Robin Meadows, who covered the study for PLoS:
The aspen clones studied ranged from roughly 70 to 10,000 years old, and pollen analysis revealed a slow but steady loss of fertility with age. Fertility was cut by more than three-quarters in the oldest clone and, based on extrapolation, would likely have dwindled away entirely by 20,000 years. Thus, though it may take millennia, even plants that grow indefinitely will eventually succumb to old age.
Still, it's clear that if you want to live for millennia, cloning yourself is the way to go.
Read the full scientific paper via PLoS Biology
Image by Tewy via Wikimedia Commons