How You Can Help (Dis)prove Evolution

The request comes from the Open University, which claims its new Evolution MegaLab project is “one of the largest evolutionary studies ever undertaken,” reports BBC News. Project leaders are asking the public to look in their gardens or in public parks for banded snails, then submit what they find online. (The “banding” refers to natural strips on the snail’s shell, not to manual band-like tags sometimes used by scientists to track animals.) Scientists hope to learn how the snails have evolved in the past 40 years in response to changes in their environments and predation.

In observing the 200th anniversary of Charles Darwin’s birthday this year, the Open University’s Jonathan Silvertown explained, “I was thinking about Darwin year and how we could help people get an idea of what Darwin was talking about.” In the case of the banded snail, Silvertown speculates on two likely influences on the snail’s “evolution”: climate change and predation by thrushes.

Darker-shelled snails are found farther north, probably because the dark shells warm up more quickly than light ones. “The climate has warmed up, so we think the distribution of colors has probably changed,” Silvertown said.

As for predation, thrushes (the snails’ primary predator) are less populous than they once were. Silvertown suggests this will decrease the frequency of snails whose colored shells match their surroundings (i.e., helping them blend in).

While “evolution” is at the center of this study (including its name), and although Silvertown claims Darwin year as the project’s inspiration, it’s actually natural selection that will explain how the banded snail population has changed. This is “evolution” only in the sense that proportions of shell features in the banded snail population are changing—not in the sense that the snails themselves are changing into anything other than snails. But watch out for the results, when announced, to be claimed as evidence for the latter definition of evolution.