Genetically, how do species evolve from a common ancestor? © BrainMass Inc. brainmass.com October 9, 2019, 5:08 pm ad1c9bdddfA typical example are the finches Charles Darwin observed on the Galapagos Islands. A flock of these birds had come at one time to these islands. Probably by a storm that brought them there from the South American mainland. Now Darwin did not know anything about the laws of genetics or about mutations but he could observe the practical results. Over the islands there were many different ecological niches. Among the finches all the time there were random (chance) ...