How Hammerhead Sharks Evolved

• Being a very strange species, scientists have always been curious over the origin of the hammerhead shark, and a new study shows that they actually evolved from much larger sharks, and the went through two more major evolutions.
• This shrinking in size is thought to be the effect of the early age at which hammerheads are able to reproduce, instead of trying to get more food to grow larger, they tried to reproduce more at young ages, resulting in a smaller species.
• Their trademark head shape was originally used by the large hammerheads to give a sort of lift underwater, the way a wing does, and although the small species does not get this same effect, they still benefit by being able to fit more electrical sensors in their noses, making prey detection much easier.
• Unfortunately, these sharks, which share similarities in growth stages as humans, are being hunted almost to extinction today.

Reflection:
Hammerhead sharks have always seemed interesting, but I have never really thought about how they came to be, so it is nice to have such a clear cut answer to an evolutionary question. The hammerheads also demonstrated how a vestigial trait, in this case their noses, can be later turned around and used as an advantage, only in a different way. What was the most curious though, was how the species grew smaller, despite the fact that a larger shark would have had more advantages. It almost seems like the species cared solely about reproducing and cared nothing for the actual fitness of its future offspring.

Source:
Staff, LiveScience. "How Hammerhead Sharks Evolved | LiveScience." LiveScience | Science, Technology, Health & Environmental News. 20 May 2010. Web. 21 May 2010. .