Ancient fish had the genetic code for limbs and fingers long before they scrambled onto dry land

Long before our ancient fish ancestors had even vaguely considered that the dry land might be a place to colonize, they had the genetic switches ready to make limbs and digits — switches which still function on mammals today.


This research was prompted by the discovery of Tiktaalik — a walking fish discovered in 2004. Tktaalik had a limb structure remarkably similar to land mammals, prompting scientists to dig into just how far back our limb coding goes.   link