Two Spats of Life
Long long ago before the the life existed, earth was very similar to Venus or Mars. It didn't have the great oddness of life and intelligence. It spun around the sun like all other dust and rocks. One day alien flew over the earth and spat on it for no reason. After spitting, he continued his journey. The spit became the first organism and life was born. The first biological addition to rocks. Mind you, there is no biological addition to Mars or Venus even till today. Because of this I am calling it abnormality to earth but can be normality beyond earth. The first organism or life grew. They grew from each other. They mixed with winds and rocks to become plants and animals always depending on each other. The first spit created a good balance of organisms. I guess the same alien must have been traveling back towards his home. He again passed by earth. He spat again. The spit fell directly on an ape. Only the ape got the alien intelligence. Dogs, cats, birds and plants were unlucky.