Spatial Data, Rocks, and Voting

Image via Matt Stiles @ NPR.

Why the blue line across the South in the sea of red? Plankton may be the answer. Read the story at Krulwich’s blog:

These same counties went mostly blue in 2004 and 2000. Why? Well, the best answer, says marine biologist Craig McClain, may be an old one, going back before the Civil War, before 1776, before Columbus, back more than 100 million years to the days when the Deep South was under water.