Water is an important biological molecule

Water and life.

Life first evolved in water for a number of reasons .

The molecules that were used by living organisms. And that made up their struernre were dissolved in the first seas.  

In the muddy estuaries and shallow seas of the primkive earth. The sinecures could become concentrated enough to react together.

Water acted as a protective shield for the first living organisms against the damaging ultraviolet rays from the sun.

Recycling water.

Life continues on this planet because water has special properties. In particular all three states of water. Solid ice liquid water and gaseous water vapory. Exist at the temperatures found on the earth’s surface. The temperature varies at different comes and at different places of the planet. But the average temperature over the earth’s surface is about 16.5c. this means that ice. Liquid water and water vapour are all present and are continually. 

Interchanging water is recycled between different parts of the environment, as shown the water cycle below.