The Nervous System is the power source of your body. Using electrical impulses, your nervous system helps control your muscle movements. The two main functions are the Sensory(afferent) division- which brings information to your brain. Then your Motor(efferent) division- which sends signals out.
A single mutation can have a large effect, but in many cases, evolutionary change is based on the accumulation of many mutations. Gene flow is any movement of genes from one population<span> to another and is an important source of genetic </span>variation<span>. Sex can </span>introduce<span> new gene combinations </span>into a population<span>.</span>