Question: do you think sharks will start to evolve over time?

Adam Hargreaves answered on 19 Jun 2017:

Hi carolinaaaa,
That’s a good question, and my short answer is that technically they’ve never stopped evolving, at least at the level of their DNA. Having said that, sharks on the whole, if you consider how they’re made up, have largely remained unchanged for millions of years.
Sharks belong to a group of animals called the Chondrichthyans, which is Greek for “cartilage fish”. This is because their skeleton is made of cartilage rather than bone. They are a very very ancient group of animals, and were around well before the dinosaurs (and any vertebrate animals which lived on land), and yet they’re still around today. This is because they are perfectly adapted to their environment and what they need to do to survive. To quote the movie Jaws, this is “swim and eat and make little baby sharks”. That’s about it!
That isn’t to say that they won’t change more drastically in the future, if something happens like the ocean becomes polluted, there’s a decline in shark populations due to shark finning etc. then they will have to adapt to that change to cope with it (or become extinct). What those changes might be, who knows! But for the moment at least, sharks have evolved to be perfect apex predators and have been successful for around 450 million years!