In terms of the real value of life to the maintenance of Earth itself then the highest form of life must surely be birds .

The fact that they can fly means for transport they are the most in tune with Earth.

In terms of this form of valuation then Man must be amongst the lowest form of life.

It could be that in the long term Man is really meant to spread life through the Universe and to leave Earth to carry on its function as the fountain-head of Life - giving a chance for other forms to reach their zenith.