Hi there! I am Charles Darwin and I am going to talk about natural selection.
Natural Selection is the process where organisms are better adapted to there environment tend to survive and produce more offspring.
This is Perry the fish and he has adapted over time to have more fins which helps it swim away from predators faster
This change did not happen overnight Perry used to only have 1 fin but after constantly being eaten by sharks it got more fins which developed over many generations
Perry and some of his friends now have little fear of sharks because they can move a lot faster then earlier generations. But some of the fish do not have this extra fin and can get eaten easier by the shark because they are slower.
The fins can vary though as Perry has extra fins and Perry's brother Max does not have extra fins. This makes Max more vulnerable to sharks then Perry because Max moves slower. This also gives Perry a reproductive advantage because female fish like male fish with more fins.