Limbs from Gills?

Could limbs have evolved from fish gills? While it might sound fishy, scientists from the University of Cambridge have discovered that the same genetic programme, triggered by a gene called Sonic Hedgehog, is involved in the development of limbs, fins and gills. The idea that the formation of gills and legs might be linked is actually not a new one and was first proposed more than a century ago based on the similarities in appearances of the two structures, but scientists abandoned the notion as fanciful thinking. Connie Orbach went to see researcher Andrew Gillis, who has discovered that the... Like this podcast? Please help us by supporting the Naked Scientists