Plymouth Elementary School first grade students celebrate the groundbreaking of the new Legoland Discovery Center at Plymouth Meeting Mall by playing in a pile of more than 50,000 Lego bricks spilled by a dump truck at the Oct. 25 ceremony. | Photo courtesy Legoland Discovery Center.
If this DNA has a mutation, the child that grows from the fertilized egg will have the mutation in each of his or her cells. Acquired (or somatic) mutations occur at some time during a personâs life and are present only in certain cells, not in every cell in the body.
What happens at the DNA level propagates up to the level of the complete organism. This example illustrates how a single mutation can have a large effect, in this case, both a positive and a negative one. But in many cases, evolutionary change is based on the accumulation of many mutations, each having a small effect.