论文部分内容阅读
变异是生物进化的起步。生物进化的另一个重要内容是选择。生物进化的结果是产生出形形色色的生物类型及其对环境的各种适应。不言而喻,没有变异,就没有进化。种内变异已知遗传物质(主要是DNA)能准确地复制自己,这有助于我们了解生物的遗传。但是,遗传总不是绝对的。这是说,同一种生物之间总有些变异。一般说,后代是亲代的复制品或拷贝。从大处讲,无疑这是对的。可是这拷贝总不会是完全的。因此,我们能够认识我们的朋友。已知人的指纹没有两个人是完全相同的。从一个指纹就经常可以鉴別那是谁
Variation is the beginning of biological evolution. Another important aspect of biological evolution is selection. The result of biological evolution is the production of various types of organisms and their adaptation to the environment. It goes without saying that there is no evolution without change. Intraspecific variation It is known that genetic material (mainly DNA) can accurately reproduce itself, which helps us to understand the inheritance of organisms. However, genetics are not always absolute. This is to say that there is always some variation between the same species. In general, offspring are copies or copies of the parent. From a great point of view, this is undoubtedly correct. However, this copy will not always be complete. Therefore, we can meet our friends. It is known that there are no two people whose fingerprints are exactly the same. From a fingerprint it is often possible to identify who