High Speed Fish Evolved Twice

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High speed fish evolved twice, according to articles in Nature, 429, p61, 6 May 2004 and BBC News 5 May 2004. Scientists at the Scripps Institute of Oceanography, USA have studied mako sharks to see how their muscles contract to enable them to be such strong swimmers. They found they had a sophisticated arrangement of muscles and tendons that directs muscle power to the tail producing a style of movement also seen in tuna, but not in other fish. Most other fish have blocks of muscle arranged along their backbones that contract in short bursts, bending the fish’s body in a wave of contraction. Tuna and sharks also have bundles of muscle specialised for longer, more sustained contractions near the centres of their bodies that are connected to their tails. This enables them to swim long distances at high speeds.

Tuna and sharks are believed to be separated by 400 million years of evolution, so the scientists believe the complex system of muscles and tendons, along with the nervous system control to coordinate it, must have evolved twice. Robert Shadwick of Scripps Institute commented: "It’s a fairly major change in anatomy to have that happen. That is the thing that is remarkable to us, that this arose independently in the two fish." This kind of double evolution is called "convergent evolution" and believed to be the result of organisms from different branches of the evolutionary tree having to live in the same environment. Because the shark and tuna muscle system is so efficient and powerful, Adam Summers of the University of California, Irvine, suggests it could help engineers design high-speed autonomous underwater vehicles.

BBC

Editorial Comment: "Convergent evolution" is a term invented by evolutionists to explain the similar design features seen in living organisms that live in similar environments or have similar lifestyles, but are on different branches on the evolutionary tree. In fact, it explains nothing. It relies on the belief that being in the same environment or having the same needs can somehow redesign an organism’s genes to produce useful structures and functions.

"Convergent evolution" is a tribute to the enormous faith of evolutionists. It takes a lot of blind faith to believe that a functional system with many interacting parts evolved once by chance random process. It takes much more faith to believe it happened twice. If anyone does ever design an underwater vehicle based on tuna and shark locomotion it will be good evidence that fish locomotion was created, rather than evolving by itself once or twice. (Ref. sharks, tuna, evolution)

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