Question: why are there so many different sharks in the world

Alex Evans answered on 15 Mar 2017:

Sharks have adapted to fill many ecological roles, mostly as predators of different types of animals (some are good at hunting fish, some are good at hunting seals, and so on) – but some sharks are also filter-feeders of tiny animals called plankton. There is a big variety mostly because there are lots of different types of food for them to eat!