What is taxonomy? It is the science of making a system. Several million species of living organisms have already been discovered on the planet. Scientists are sure that millions more representatives of animals, plants, fungi and microorganisms are to be discovered. All this diversity needs to be systematized.
What is taxonomy in zoology?
Each branch of biology began to carry out serious work to systematize the world of wildlife in due time. The foundations of the taxonomy of the animal world were laid by Aristotle, a famous ancient Greek philosopher. Large taxa introduced by Aristotle are still in use today.
What is taxonomy in zoology? This is one of the disciplines of zoology. All disciplines that make up the science of animals are closely related to each other. At the same time, they are independent to a certain extent: morphology, physiology, ecology, zoogeography, paleontology, phylogenetics, systematics.
What is taxonomy in zoology? A science that studies the diversity of animals and establishes, depending on the degree of similarity, the order of subordination. Systematics in zoology builds the classification of animals.
Hierarchy of taxa
To compilesystems of the animal world, scientists use the hierarchy of taxa: kingdom - type - class - order - family - genus - species. Any organism discovered and described by scientists is included in each of the presented taxa.
In the 18th century, Carl Linnaeus introduced binary nomenclature. That is, each type of organism has its own name, consisting of two words. The first word is the generic name. This principle of naming makes it easier to understand what kind of animal we are talking about, because there are still much fewer genera in the system than species.
Kinship of species of organisms
Since the time Charles Darwin put forward the theory of evolution, taxonomy has been based on the principle of relationship of organisms to each other. All organisms belonging to the same taxonomic group are more closely related to each other than to other types of organisms. That is, they came from one common ancestor.
How scientists work
Carl Linnaeus systematized animals based on external similarities. Currently, scientists use many approaches to most accurately determine whether a species belongs to a particular taxonomic group. Anatomy data is used, that is, the external and internal structure of organisms is considered. Physiology data adds information to more accurately classify animals. Paleontology makes an invaluable contribution to determining the origin of organisms, which is very important when compiling a system, because it is the family ties of the course of evolution that are taken into account when classifying animals and other organisms. Genetics is making an increasing contribution to taxonomy. It provides data on DNA sequencing results.
The genomes of different organisms are compared. The entire system of the world of wildlife is being corrected.
For example, until recently, the Australian emu and the American rhea were ostriches. After some new data from genetics and other sciences appeared, scientists came to the conclusion that only the African ostrich is actually an ostrich. Emu and rhea are not related to each other or to the African ostrich. The fact that these species are so similar in appearance is the result of convergence in evolution. This similarity arose due to the same lifestyle of these birds. African ostrich, emu and rhea never fly, prone to flee from predators.
Mammal Systematics
Mammals are characterized by hair, homoiothermia (warm-bloodedness) and the presence of mammary glands.
Currently, according to various sources, the class of mammals consists of 2 or 3 subclasses: first beasts, marsupials and placentals. In the case of the division of mammals into 2 subclasses of marsupials and placentals, they are classified as a subclass of real animals.
The first animal is a platypus and five types of echidnas.
These representatives have all the characteristics of mammals, but at the same time they lay eggs, as did their distant ancestors - animal-like reptiles. It is believed that all modern mammals originated from animal-like reptiles.
Marsupials areintermediate stage in the course of evolution. They no longer lay eggs, but the placenta is poorly developed in lower animals. That is why marsupials give birth to premature babies, which are carried in a bag.
Placental mammals have a developed placenta - the organ that connects mother and baby.
Let's imagine the systematics in the table:
| Taxon | 1 | 2 | 3 |
| Subclass | First Revealed | Marsupials | Placental |
| Squad1 | Single pass | Marsupials | Insectivores |
| 2 | - | - | Baptera |
| 3 | - | - | Rodents |
| 4 | - | - | Lagomorphs |
| 5 | - | - | Predatory |
| 6 | - | - | Proboscis |
| 7 | - | - | Pinnipeds |
| 8 | - | - | Cetaceans |
| 9 | - | - | Artiodactyls |
| 10 | - | - | Odd-toed ungulates |
| 11 | - | - | Primates |
Thus, the systematics of mammals, like other taxonomic groups of animals, plants and microorganisms, is a constant process of data improvement. The development of genetics in the 21st century has led to great changes in the system of the world of wildlife.
