The Hidden Warning of Fall Colors - Issue 27: Dark Matter
▻http://nautil.us/issue/27/dark-matter/the-hidden-warning-of-fall-colors
Drifting above North America last autumn, a NASA satellite named Terra partook in some high-altitude leaf peeping. In an aerial photograph snapped in September, swaths of orange and red saturate the green landscape, as if igniting the planet in a smokeless blaze. If an alien spacefarer were to happen upon this annual scene, it might mistake the spectacle for an intentional signal—a battle flare, perhaps, or a distress call. Earth-bound scientists, on the other hand, long dismissed autumn colors as a mere coincidence. “Such biochemical extravagancies … seem to have no function in the trees,” wrote one plant physiologist in 2000, echoing the sentiment of the 19th-century Scottish biologist Marion Newbigin. But in the late 1990s, William D. Hamilton, an evolutionary theorist at Oxford, (...)