How does evolution play a role in the differences in tail movement of marine animals?

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the

Where is the picture at

My pigs teeth have already came in years ago, with my first molars, and my second molars are pretty much in. my wisdom teeth will be unable to come in, but i'm getting those out on monday.