The tendency to classify things is inherent in man since eternity, and stems from our desire to organize the world and understand the laws governing it. In everyday life people classify objects according to their needs and comfort, and everyone does so differently. For example, there are people who classify blocks according to their subjects, others classify them according to the author's name, and a third group according to the size of the book, and other classifications.
Scientific classification of living creatures depends on the characteristics of the body, and is based on many qualities and not just one attribute: qualities associated with the body and behavior of creatures and in recent years in the building of the genetic material (DNA) also.
All of these qualities make it possible to draw conclusions about the living creatures and the relationships between them.
For example:
Shark and dolphin are similar in that they live in water. The mouse, unlike others, lives on land. But the shark breathes through the gills, its embryo develops inside eggs, its body temperature is not fixed, while the dolphin and the mouse breathe through the lungs, their fetus develops in the womb inside the mother's body, and their body temperature is fixed. The genetic material (DNA) of the dolphin is more similar to that of the shark. Indeed, dolphins and mice follow the same category (mammals) at a time when the shark follows another species (fish).
Scientific classification of living creatures depends on the characteristics of the body, and is based on many qualities and not just one attribute: qualities associated with the body and behavior of creatures and in recent years in the building of the genetic material (DNA) also.
All of these qualities make it possible to draw conclusions about the living creatures and the relationships between them.
For example:
Shark and dolphin are similar in that they live in water. The mouse, unlike others, lives on land. But the shark breathes through the gills, its embryo develops inside eggs, its body temperature is not fixed, while the dolphin and the mouse breathe through the lungs, their fetus develops in the womb inside the mother's body, and their body temperature is fixed. The genetic material (DNA) of the dolphin is more similar to that of the shark. Indeed, dolphins and mice follow the same category (mammals) at a time when the shark follows another species (fish).
