Evan: This is a picture of sharks eating. One is eating a snail, another is eating a fish and the other is eating a crab. The big shark is going to eat everyone!

Dear Evan, The sea environment has changed a great deal in the last few decades. Did you know that sometimes people use the ocean to dump chemicals or garbage that they can't put anywhere else? Once, when my dad was fishing in Austraila, he caught a shark by accident. He tried to get it off the hook but the shark was too badly injuried and it died. My dad felt very bad. Do you think that animals might become endangered because sometimes what people do is an accident? Ms. R-M

Extinction is how the old ones disappeared and how the new ones formed. How can new things form when the old thing has disappeared? It won't be the same thing that would have disappeared. It would have to look different. I think that the braciosaurus turned into the giraffe because of the long necks and they look the same. I think the Triceratop turned into the rhino because of the horns. They have same things but the skin turned into fur. I am interested in studying dinosuars like the t-rex. I think it might be related to the lizard. It's like puzzle pieces.

Sean Bell replies: What you are touching on is a phenomenon called CONVERGENT EVOLUTION. This is when very unrelated animals (like giraffes and brachiosaurs) share a common feature (long necks). Although they may look similar, there is no direct line between them. The changing of old animals into new ones is called evolution. What you find is that new species often look very similar to the old one that gave rise to it--so no, the new species won't be the same thing as the one that disappeared, but it should be similar. Part of the work of paleontologists and biologists is to figure out which fossils have any relationship to living animals or to other fossil animals.