Our planet is a planet of water. The oceans which cover three quarters of the surface of the earth(ground), represent about 1300 millions of km3 of water. In this this immense spread(widened) liquid, are in dissolution of minerals variously and gases necessary for the foisonnante life, and of an almost inconceivable multiplicity, which conceal seas. The aquatic animals inhale the dissolved oxygen, plants, taking advantage of some dissolved very carbon dioxide, elaborate of the food.

The ocean shelters thousands of animal and vegetable species today among which each is magnificently adapted to the environment. Both coexist in a natural balance, an outcome of the evolution through ages. This cradle of the life, nevertheless, did not still exist.

When our planet was there only for its beginnings and that formed and cooled the earth's crust, there was no sea. At a premature stage(stadium), the water freed(released) by our warm planet became vapor and rose, the captivating in a vast cloud. Then she(it) cools, condensed and fell again on earth(ground) in almost permanent thunderstorms, to be vaporized and go back up(raise) still. This " cycle of the dry water » repeated millions of times before the earth(ground) is cold enough so that the water can live there and accumulate in cracks and depressions: the forming(training) of the original sea had begun. A billion years was credibly needed so that the oceans are full.

If it was necessary to us to redraw the infinitely slow and long class(course) of the evolution, we would leave both most evolved forms of life which had to appear: the man, the most intelligent of the ground creatures, and dolphin(dauphin), the most intelligent of the maritime animals. Both belong to the same class; both are Mammals, Vertebrates practising the feeding of their small. Both lower(go down) primitive Mammals which roamed on earth(ground), the current Cetaceans having returned to the sea having lived certain time on continents.

These prehistoric Mammals were the heirs of the cold-blooded vertebrates, themselves stemming from the first fish which succeeded in crawling outside the water and in complying in the conditions of life ground. This transition required(demanded) the adaptation to the gravity, which is not felt under the water, and the absorption of oxygen from the air(sight) and either the water. These fishes with air breath and which moved on earth(ground), resulted in turn from the evolution, in the course of million years and through various stages, of primitive animals divested of dorsal thorn, distant downward of unicellular forms. But even before the oceanic fauna begins to evolve, animal and plant kingdom differed. The bodies which acquired the capacity to use the solar energy to elaborate their own food, from dissolved mineral substances in the sea, "specialized" as plant. Others, not enjoying this faculty(power) but capable of pulling(firing) plants their subsistence, formed the animal kingdom. Obviously, animals also learnt(taught) in enters to waste(destroy).

The man has the illusion that the oceans and the continental masses of our universe are eternal and that it is himself the fruit and the term of billion years of evolution.

There are, certainly, reasons for thinking that the rhythm in which new forms of life are produced considerably slowed down. The Earth, however, continues not less(nevertheless) to change, whereas the man influences in a alarming way this fragile process. His(her,its) influence is destructive today tragically but he(it) takes there place to hope that the Science and the Reason will knock down the tendency. Be that as it may, the future world will certainly be so different from ours as ours is it of the Prehistory.

If we levelled the earth's crust, if we levelled the big mountain massifs, such Himalaya, and if we filled oceanic pits as those the Philippines(Filipinos), the Earth would be covered by a coat(layer) of uniform water of more than 3 km in thickness! Such is the blunder of the ocean. The Earth is really a planet of water. Nevertheless, it is another way of considering her(it), more suited maybe when it is about the man. All the water of the earth(ground), sweet or salty, represents only a little more thousandth of the ground volume. In this optics, we understand better that it is necessary to protect and to love this vital but limited resource. The water returns our livable planet. In fact, it is life. She(it) modifies the climate by storing the heat and by redistributing it on earth(ground) thanks to the common(current) sailors and to the atmospheric traffic. The water is the universal solvent: she(it) dissolves a bigger number of substances than any other liquid. At the man, the water conveys the vital materials(subjects) through all the body, and so allows the complex biochemical reactions which establish(constitute) the life. Precious and rare Don, that the water!