It's Easy to Be Fearless When You Have a Good Shell

Aesop never penned a fable about a snail. If he had written about a certain freshwater mollusk, the moral might have been Boldness comes from a strong shellor maybe Careless snails get chomped. But because the snail and its variable shell are real, their lesson has more to do with the the weird workings of evolution. Individual Radix balthica snails can have differently shaped shells. They also have varying "personalities," at least as far as you can measure such a thing in a mollusk. To see whether their shells and personalities were linked, Johan Ahlgren, a researcher at Lund University in Sweden, gathered snail eggs from four nearby ponds. Back in the lab, Alberg waited for the eggs to hatch. He fed the young snails algae and lettuce until they were grown. Then he subjected the animals to a personality test. The trait that interested Ahlberg and his colleagues was ...