Lopsided gene proves humans are distant cousins of snails!
by PZ Myers
A gene shared by birds, fish, reptiles, people – and snails – reveals the fundamental relatedness of all living creatures… Snails have nodal signaling!
I know, you’re positively floored. Amazing! Enthralling! Say no more; the implications are simply awesome.
Look at yourself in the mirror. You’re probably mostly symmetrical: one eye and one ear on each side of your head, features that are at least roughly even, and any lopsidedness is most likely due to postnatal wear and tear.
Deep inside you, though, you are profoundly asymmetrical, and that asymmetry is essential for your well-being. The speech centres of your brain are mostly on the left side, the left side of your heart is larger and more muscular than the right, your stomach coils to the right and the bulk of your liver is on the left, and your large intestine loops just so, with your appendix on the right. With a few medically interesting exceptions, we all have guts consistently skewed in a particular orientation…
(read more: Guardian UK) (image: Corbis)