The Shark : The Predator Essay

1486 Words Jun 7th, 2015 6 Pages
“The shark is the apex predator in the sea. Sharks have moulded evolution for 450 million years. All fish species that are prey to the sharks have had their behaviour, their speed, their camouflage, their defense mechanisms moulded by the shark.” – Paul Watson. Sharks are cartilaginous fish with pair fins and nares, two chambered hearts and jaws. These characteristics are unique to the class, chondrichthyes. Ray, skates, and chimaeras are members of this class and sharks closest relatives.

Shark fossil aren’t like dinosaur fossils, because sharks skeletons are made of cartilage (a connective tissue) they don’t fossilize well at all. However shark teeth and scales (called dermal denticles) do fossilize well and those fossils teach us up the prehistoric sharks and what they went through.

Sharks have survived all 5 mass extinctions. Each eradication resulted in changes to the environment, which can be difficult to quickly adapt to. 251 million years ago 95% of all species were killed in what is called the “Great Dying”; sharks made it through this. Being one of the few surviving species in a mass extinction gives you the chance to flourish. When previous predators are killed and new habitats open up you are given an adaptive radiation. Adaptive radiation is when organisms become more diverse rapidly. The change in environment that mass extinctions result in makes new resources available and niches open up. These factors created speciation and phenotypic adaptations in…

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