By Susan Milius
The term “bar fight” does not actually appear in Saila Varis’ recent paper in the journal Trees or in her Ph.D. dissertation on the Scots pine. But she’s a good sport about discussing whether her research suggests that tree pollen grains have their own versions of nose-punching brawls over female favor.
After all, pollen grains from genetically different trees of the same species appear to be able to sabotage each other’s race to a mate, says Varis, of the Finnish Forest Research Institute near Helsinki. Though it is not exactly like a bar fight, she says, there are hints of male-versus-male competition.
Plant pollen may be basically microscopic dust, but as far as evolutionary biology goes it can be as male as any swaggering pool-hall hound with smooth moves and high hopes for the night. Pollen grains competing for access to the alluring green nubbins of female tissue in a pine tree add to growing evidence that a quirky evolutionary force known from animals, called sexual selection, may also show up in plants.