What does systematics study in biology?
Scientific discoveries were made differently at all times: after millions of repetitions and experiments, or, conversely, by chance, not to mention insights and revelations and dreams. But no science could have avoided such an important stage - the most difficult, badly necessary for becoming and developing, as the classification of accumulated knowledge, discoveries, experiments of eminent scientists and random discoverers. Systematics in biology puts forward and in practice checks the possible principles of combining all living organisms into a single hierarchical structure. It is also called taxonomy, but it is a more general name for any classification.
What does systematics in biology study?
In 1735, the Swedish naturalist Karl von Linney (physician, pathologist, botanist, zoologist) published a scientific work called “The System of Nature”. He is considered the founder of systematics. At that time, biology was in place due to the large fragmentation of accumulated scientific data described at that time animals and plants and the lack of a common nomenclature for them.Thanks to Lynne, she received a new powerful impetus, which a century and a half later turned into the theory of evolution in Darwin’s book The Origin of Species.
What kind of species? Lower rank, junior taxon in biological systematics. Together with the genus - the strict name, the exact address of each living organism in the hierarchical system of all known biomass of the Earth. Therefore, taxonomy studies biological diversity in order to create a scientifically based classification.
Natural and artificial systems
Linnaeus himself called the system developed and proposed by him artificial. And he predicted that followers — future naturalists — would be able to create a natural biological system. The systematics proposed by Linney is a science that studies the external structure of organisms and classifies them on this basis. The scientist identified similar signs of organisms and then ranked them in the same group. But he did not disclose the reasons for the identity of species, genera, classes, orders for the chosen attribute, hoping that the descendants will be able not only to improve his system, but also to explain the similarity of different taxa.
The first proposed a harmonious theory of Charles Darwin.The genius of his predecessors, including Linnaeus, lies in the fact that many species were correctly placed in one taxon. Relying on an external feature, scientists intuitively correctly determined that organisms are united by one common ancestor, from which his younger ones inherited in the tree of life “relatives”. In fairness, I must say that there were many mistakenly combined into a family or genus of organisms.
Evolution Theory at the Basis of Systematics
Thanks to Darwin, the artificial system was replaced by a natural classification - based on kinship. She retained the nomenclature of the Linnaean system and was not so much a complete replacement for the previous one, but its natural continuation and expansion. All this happened gradually, as scientific discoveries and the discovery of various fossils. The latter also acquired their address in the biological system. The extinct organisms at the moment are what systematics studies and searches for especially carefully. More and more features are being proposed to identify common ancestors of the species, and therefore places nearby in the hierarchy.
Systematics of animals
In parallel with the distant ancestors of the currently existing species, the animal taxonomy studies what else can be accepted as a general attribute for classification.
Embryological features, physiological similarity of organisms (nutrition, respiration, etc.), cell structure, chromosomal apparatus are distinguished. Indeed, much of this has become possible to explore thanks to scientific and technological progress, which since the 18th century continues to gain momentum around the world.
Despite the fact that the taxonomy studies and improves many signs of belonging to one taxon, it is difficult even at the level of the great rank of the kingdom animals to distinguish a number of unique features peculiar only to animals. For example, such:
- The vast majority of animals need oxygen, but not all.
- Animals - heterotrophs, they consume ready-made nutrients, in contrast to plants - autotrophs. But there are single-celled animals with a mixed type of food.
The simplest and first division of the animal kingdom begins on the principle of structure. The main “brick” is a cage, probably the most unique sign of belonging to the animal kingdom, which systematics studies. The division of the whole kingdom into taxa begins with it. The first on top are two sub-kingdoms - multicellular and unicellular. The latter is also called the simplest.
Based on the fact that the structure of the cells of all animals is similar, it is believed that multicellular developed from single-celled. But on how it happened, who was the so-called missing link between them, there are only a number of theories.
Systematics of plants
Primitive algae, according to the theory of the origin of species, became not only the ancestors of existing plants, but also a link in the food chain of animals.
What is studying plant systematics at the moment? Despite the fact that plants do not have a skeleton, therefore, the fossil remains of their ancestors are not so much preserved as animals, all the same, scientists are talking about the evolution of plants. All departments in the plant kingdom can be divided into two conditional groups. The lower divisions include several sections of algae, the highest divisions are flowering (or angiosperms, divided into monocots and dicots), gymnosperms (the most famous of them are conifers) and spore divisions — ferns, lichens, and moss.
View - a unit of taxonomy
There are two approaches in determining the belonging of a species to each of the senior taxa, and they have developed historically. The first is by external signs, the second is evolutionary, in accordance with possible or known common ancestors of the studied organism and other members of the taxon.
A species is a basic rank, a taxonomic unit. This is what systematization studies in the first place, the ultimate goal of this field of biology. But all the new species and traits for their classification are offered by the modern world with the development of many sciences, so the work of biologists in the field of taxonomy has not yet been completed.