Listen to me, please.Youre like me, a homo sapiens, a wise human.Life, a miracle in the universe, appeared around 4 billion years ago.And we humans only 200,000 years ago.Yet we have succeeded in disrupting the balance so essential to life.Listen carefully to this extraordinary story, which is yours, and decide what you want to do with it.These are traces of our origins.At the beginning, our planet was no more than a chaos of fire, a cloud of agglutinated dust particles,like so many similar clusters in the universe.Yet this is where the miracle of life occurred.Today, life, our life, is just a link in a chain of innumerable living beings that have succeeded one another on Earth over nearly 4 billion years.And even today, new volcanoes continue to sculpt our landscapes.They offer a glimpse of what our Earth was like at its birth, molten rock surging from the depths,solidifying, cracking, blistering or spreading in a thin crust, before falling dormant for a time.These wreathes of smoke curling from the bowels of the Earth bear witness to the Earths original atmosphere.An atmosphere devoid of oxygen.A dense atmosphere, thick with water vapor, full of carbon dioxide.A furnace.The Earth cooled.The water vapor condensed and fell in torrential downpours.At the right distance from the sun, not too far, not too near, the Earths perfect balance enabled it to conserve water in liquid form.The water cut channels.They are like the veins of a body, the branches of a tree, the vessels of the sap that the water gave to the Earth.The rivers tore minerals from rocks, adding them to the oceans freshwater.And the oceans became heavy with salt.Where do we come from?Where did life first spark into being?A miracle of time, primitive life forms They give them their colors. Theyre called archeobacteria.They all feed off the Earths heat.All except the cyanobacteria, or blue-green algae.They alone have the capacity to turn to the sun to capture its energy.They are a vital ancestor of all yesterdays and todays plant species.These tiny bacteria and their billions of descendants changed the destiny of our planet.They transformed its atmosphere.What happened to the carbon that poisoned the atmosphere?Its still here, imprisoned in the Earths crust.Here, there once was a sea, inhabited by micro-organisms.They grew shells by tapping into the atmospheres carbon now dissolved in the ocean.These strata are the accumulated shells of those billions and billions of micro-organisms.Thanks to them, the carbon drained from the atmosphere and other life forms could develop.It is life that altered the atmosphere.Plant life fed off the suns energy, which enabled it to break apart the water molecule and take the oxygen.And oxygen filled the air.The Earths water cycle is a process of constant renewal.Waterfalls, water vapor, clouds, rain,springs, rivers, seas, oceans, glaciers.The cycle is never broken.Theres always the same quantity of water on Earth.All the successive species on Earth have drunk the same water.The astonishing matter that is water.One of the most unstable of all.It takes a liquid form as running water, gaseous as vapor, or solid as ice.In Siberia, the frozen surfaces of the lakes in winter contain the trace of the forces that water deploys when it freezes.Lighter than water, the ice floats.It forms a protective mantle against the cold, under which life can go on.The engine of life is linkage.Everything is linked.Nothing is self-sufficient.Water and air are inseparable, united in life and for our life on Earth.Sharing is everything.The green expanse through the clouds is the source of oxygen in the air.70% of this gas, without which our lungs cannot function,comes from the algae that tint the surface of the oceans.Our Earth relies on a balance, in which every being has a role to play and exists only through the existence of another being.A subtle, fragile harmony that is easily shattered.Thus, corals are born from the marriage of algae and shells.Coral reefs cover less than 1% of the ocean floor, but they provide a habitat for thousands of species of fish, mollusks and algae.The equilibrium of every ocean depends on them.The Earth counts time in billions of years.It took more than 4 billion years for it to make trees.In the chain of species, trees are a pinnacle, a perfect, living sculpture.Trees defy gravity.They are the only natural element in perpetual movement toward the sky.They grow unhurriedly toward the sun that nourishes their foliage.They have inherited from these miniscule cyanobacteria the power to capture lights energy.They store it and feed off it, turning it into wood and leaves,which then decompose into a mixture of water, mineral, vegetable and living matter.And so, gradually,soils are formed.Soils teem with the incessant activity of micro-organisms, feeding, digging, aerating and transforming.They make the humus, the fertile layer to which all life on land is linked.What do we know about life on