The branch of biology that studies the methods and principles of biological classification. Classification refers to following the principles and methods of taxonomy to name and grade all kinds of organisms.
After the Swedish biologist Linnaeus named creatures, later biologists classified them by domain, realm, phylum, class, order, family, genus and species.
The top boundary, the five boundaries proposed by Whittaker, is accepted by many people; They are animal kingdom, protozoa kingdom, fungi kingdom, plant kingdom and animal kingdom. From the highest "boundary" to "species", the lower the level, the more similar the characteristics of the creatures they belong to. * * * There are seven categories, namely: phylum, family, genus and species.
Extended data
Biology has a history of about 4 billion years in the history of the earth. About 6.5438+0.5 million species of organisms have become extinct, and some of their remains are preserved in the strata to form fossils.
Paleontology specializes in studying organisms in geological history through fossils. Early paleontology mainly focused on the classification and description of fossils. Later, various branches of biology were introduced into paleontology, resulting in branches of paleoecology and paleogeography. It has been suggested that paleontology, which was originally limited to the classification and description of fossils, should be replaced by paleontology in a broad sense.
There are so many groups of organisms that a special subject is needed to study the division of groups. This subject is taxonomy. The classification in Linnaeus period is guided by the theory of species invariance, and it is only classified according to some distinguishable characteristics, which is called artificial classification.
Modern classification is based on the theory of evolution, and it is called natural classification according to the evolutionary distance of species. Modern taxonomy not only compares the morphological structure, but also absorbs the achievements of biochemistry and molecular biology at the molecular level, thus revealing the evolutionary relationship of organisms more deeply.
Many branches of biology are divided according to the properties, characteristics or life processes of life movements.
Baidu encyclopedia-biology