Human evolution
Research has shown that human beings are genetically rather similar. The DNA of individuals is more alike than usual in most species. This may have resulted from their relatively recent evolution or from the Toba catastrophe. Skin colour is an adaptation to differing climates. These traits are a very small component of the Homo sapiens genome and include such outward characteristics as skin color and nose shape, and internal characteristics such as the ability to breathe more efficiently at high altitudes.