Answer:
<em>The principle of common descent states that all organisms in the world exist because of a common ancestor which gave rise to all the life seen on Earth. The organisms which are more closer to one another might have a common ancestor in the near past as compared to other organisms. The organisms which share distant common ancestors have less common characteristics. This principle has led us to form the basis for the formation of evolutionary biology. </em>
<span>Observation of the solar system support the nebular theory because all planets orbit the sun in the same direction and in roughly the same plane.</span>