Chelsea Wald and Bob Hirshon, AAAS, the Science Society
Bob - This week for the Naked Scientists, squirrels locked in a life and death struggle with spruce trees. But first, Chelsea has this report on a new theory of how life could exist in the extreme conditions of Mars.
Chelsea - Despite some curious data, most scientists believe the Viking missions of the 70s didn't find signs of life on Mars. But now astrobiologist Dirk Schulze-Makuch of Washington State University says the data may suggest life of a different kind. On Earth, life is based on water, which would freeze on Mars. But Schulze-Makuch points out that life based on a mix of water and hydrogen peroxide could survive.
Dirk - The hydrogen peroxide-water solution is actually quite neat in that way that it would allow near-surface life on Mars at current conditions. And not only that, it would explain nicely the Viking result.
Chelsea - If this sort of life does exist-and it's still a huge if - he suspects it would be tiny and single celled. He adds that the experiments Viking performed not only would have missed this life-they almost certainly would have killed it.
Bob - Thanks, Chelsea. Well, it's not as sensational a survival story as life on Mars or at the bottom of the ocean, but the red squirrel and the white spruce are locked in an epic battle over seeds. Scientists thought the tree had found a winning tactic: starve the squirrels of seeds for several years and then produce a bumper crop just when its enemies' numbers are low. But ecologist Stan Boutin of the University of Alberta says even that wasn't enough.
Stan - The squirrel has countered this strategy by actually anticipating when the trees are going to produce the big amounts of seed and producing another litter of babies. So the squirrels have produced a counterstrike against the trees.
Bob - And as in all great epics, the protagonist's downfall is of his own making. Boutin says the tree may inadvertently reveal its intentions to the squirrel through the hormones in its buds.
Chelsea - Thanks, Bob. Next time we'll join in the discussion about pain and suffering-we hope without causing you any. Until then, I'm Chelsea Wald.
Bob - And I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists.