A mother’s hidden genes decide which way her snail baby spirals

With a bit of penmanship, ‘e’ and ‘9’ can be made to look like mirror images of each other. While the ‘e’ swings counter-clockwise, the ‘9’ swings clockwise, written from top to bottom. Snails also can be similarly left- or right-handed depending on which way their shells coil. 

But what decides which way the shell turns? Recently, scientists from the U.K. and Japan found the answer for Japanese Euhadra snails.