Dvar Torah from Rabbi Menachem Schrader, founding director of JLIC.

One of the surprising features of the Six Days of Creation is that Man and land animals share a day of mutual formation. Our own human sense of pride almost begs; don’t we deserve a day of our own? Couldn’t God have included the land animals with the sea and bird life of the fifth day? Could not things have been divided to provide Man with his oen day of creation glory to bask in?
Rabenu Nisim of Gerona asks this question, and gives the following answer:
The distinction between Man and Animal is not going to be something God will divinely decree. It is a distinction that will have to be made by Man himself. Man does have the spiritual capacity to be on acompletely different plane than his animal neighbors. He also has the potential to ignore that capacity and fit right in with the animal kingdom. Whether Man will be spiritually distinct or not will be decided by his actions. God does not artificially separate Man from the animals. God grants Man the option of distinguishing himself. It is his freedom to decide.
The jury on this one is still out.