Convergent evolution

The study “Convergent evolution in mechanical design of lamnid sharks and tunas” by Jeanine M. Donley and colleagues explores the convergent evolution between lamnid sharks and tunas. The goal of this study was to gain information on the swimming kinematics of lamnid sharks and demonstrate the convergent evolution by looking at the similarities between morphology and functionality. Because of the great size and risk of studying these sharks, there is little information prior to this study about the movement of these sharks. To study this, in vivomechanisms, such as electromyography and sonomicrometry, were used to examine the contractions of red and white muscles while swimming I. oxyrinchus,shortfin mako sharks, in a swim tunnel. This was done to test if the lamnid sharks, like tunas, uncoupled the shortening of red muscles from the shortening of white muscles and deformation of the skin and backbone. Also, a combination of mechanisms were used to study the 3-demnsional morphology of the myosepta, a tendinous connective tissue.