“生命”是由地球上共存的无数生物的基因组决定的。正是基因的多态性造就了不同的物种，甚至也决定了物种内个体间的差异。DNA作为生物大分子，其本身还有诸多的未知领域有待探索，其超螺旋的不同存在状态以及这些状态对生命的意义至今尚未清楚。基因的多态性与人类的生活密切相关，它的存在导致了各种各样的遗传疾病;另一方面，也能够利用它与疾病基因之间的关系来检测疾病的存在，甚至用于治疗。多态性决定了个体的存在与个体间的细微差异，如人类的指纹、掌纹等。溯本求源，现在通过基因水平的检测能利用这种多态性进行精确的身份识别。

"Life" is decided by genomes coexisting in numerous organisms on the Earth. It is gene polymorphism that is creating different species, or even determines the difference among individuals within a species. As biological macromolecules, in DNA there are still many unknown fields to be explored, and the different states of its supercoil and the meaning of these states for life have not yet been clearly konwn today. Gene polymorphism is closely related with human life. Its existence leads to a variety of genetic diseases; on the other hand, we can use the relationship among disease genes to detect the presence of the diseases, and even to treat these diseases. Polymorphism determines the existence of individuals and slight differences between individuals, such as human fingerprints，palm prints,etc..Tracing the origin,by the detection on the level of genes, we can use polymorphism to do accurate individual identification.