As early vertebrates transitioned from an aquatic lifestyle…
As early vertebrates transitioned from an aquatic lifestyle to terrestrial habits (like Tiktaalik!), major changes in structural and physiological characteristics made their survival possible. It is likely that some of these traits are a result of _________. An artist’s recreation of Tiktaalik roseae. By Zina Deretsky, National Science Foundation (Courtesy: National Science Foundation) , via Wikimedia Commons