We're Right-handed or Left-handed...
And so are shells! Snails have coiled shells, and most coil in the right-hand direction: if you look at the shell with its tip pointing up, the opening is on the right side. These are called dextral shells, in contrast to left-handed ones, called sinistral. It’s long been suspected that the coiling direction, also known as chirality, is determined by a single gene. This was confirmed recently by Japanese researchers Masanori Abe and Reiko Usuda. Using complex gene-editing te