What’s the News: British scientists searching for signs of climate change in banded snail shells have completed one of the largest evolutionary studies ever, a massive survey across 15 European countries. Their research associates? More than 6,000 snail-hunting volunteers.

How the Heck:

Banded snails are sensitive to the sun, and lighter-colored shells reflect more sunlight than darker shells, helping them keep cool. The scientists in charge of the study, run by Open University, hypothesized that the 1.3° C climb in temperature since the 1950s would have given lighter snails an evolutionary advantage. Armed with shell color data from the ’50s through the ’90s, they set out to see if the number of light snails had grown.
To get samples from the present day, they enlisted the help of volunteers through the Evolution Megalab project, launched in honor of Darwin’s 200th birthday in April 2009. Volunteers registered on the site, learned to identify the different colors of snail shell, and set out scrounging around hedges and weeds over the course of six months. They submitted data sheets online, marking where they had found the snails on Google Maps so scientists could tell what habitat they were in—grassland, hedgerow, ...