Snake (source code)
= Snake
A <snake> is a member of an elongated, predominantly limbless reptile lineage within <Squamata>. <Limb> reduction is one feature of its evolutionary history, not evidence that the lineage has no relationship to limbed ancestors. Different snakes retain different remnants of the ancestral limb-development system.
A study of a <limb> regulatory <enhancer> found progressive functional loss in snake sequences. Replacing the corresponding <enhancer> in mice with a snake-derived sequence produced severe <limb> reduction, linking a regulatory <DNA> change to developmental output. <Progressive Loss of Function in a Limb Enhancer during Snake Evolution by Evgeny Z. Kvon and others>[2016, abstract and genomic enhancer-replacement experiments]{ref} This identifies a contributing mechanism; it does not show that one sequence change alone explains every anatomical specialization of snakes.
Back to article page
