Snails and humans use same genes to tell right from left


A yellow and brown side-by-side pair can be seen at the right; the one closer to the
middle of the photo is dextral, and the other is sinistral. (Nipam Patel/UC Berkeley)

“Biologists have tracked down genes that control the handedness of snail shells, and they turn out to be similar to the genes used by humans to set up the left and right sides of the body.

“The finding … indicates that the same genes have been responsible for establishing the left-right asymmetry of animals for 500-650 million years, originating in the last common ancestor of all animals with bilateral body organization, creatures that include everything from worms to humans.”