“With immortality comes immobility.
Because some quaking aspen trees can reproduce by copying themselves, some people have wondered whether they might live forever, at least theoretically. But even if that’s possible, they’re still not immune from the ravages of time.
As aspen clones grow older, a slow buildup of genetic mutations impairs their pollen production. After a few tens of thousands of years, they won’t produce any pollen at all.
When that happens, trees will still be able to sprout clones from their root tips, but they won’t be able to make seeds. They’ll be stuck in place, vulnerable to disease or disaster.
“There’s a slow and steady loss of fertility with age,” said San Diego State geneticist Dilara Ally. “Because we were able to calculate the rate at which male fertility was lost, we could estimate how long it would take fertility in the oldest clone to dwindle away entirely.”
From the time they’re seedlings, quaking aspens like those studied by Ally reproduce clonally, sprouting new trees from specialized root tips. As they mature, they also start to self-fertilize, producing clonal seeds. In both cases, the resulting tree is a copy of the original.
Individual trees have a lifespan of about 200 years, but clones — scientists consider the collective as as single entity — can sprawl for acres, all descended from one original tree, and apparently able to reproduce indefinitely.”
Read more at Wired
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