Trees can't live forever without sex, study shows
Certain trees are able to clone themselves, which raises the tantalising possibility that they could effectively "live forever".
But a study published in the journal PLoS Biology has dashed that hope.
Dr Dilara Ally and her team at the University of British Columbia, Canada, found that the fertility of clones declines with age.
This means that a tree cannot clone itself indefinitely; it must eventually sexually reproduce, or it will die.
The secret of eternal life has been sought by human alchemists for centuries, but certain trees were thought to have evolved the knack, through cloning.