The concept of living being is a very general denomination that can be applied to any organism that has some function of life (reproduction, nutrition or energy consumption).
When we speak of a living being, we are including any plant or animal, but also bacteria (but not viruses, which do not feed or have the functions of other living beings).
The role of biology and its various fields
The science that studies the whole of life is biology, a knowledge that is oriented to the different structures related to life: zoology, botany, ethology, medicine, genetics and a long list of disciplines (some of them have aspects related to life and others that are not, such as sociobiology). In any case, the idea of living beings is opposed to that of inanimate beings, such as light, air, water or minerals.
Aristotle and the first reference
The notion of being alive as a concept that explains a part of nature was already used in antiquity and specifically it was Aristotle in the IV century BC. C who made the first classification of living beings, focusing especially on animals (he divided them into those with blood and those without).
Linnaeus established the new foundations that we know today
Their classification was in force until the 18th century AD, when the Swedish naturalist Linnaeus introduced a more elaborate classification system based on the similarities in structure between the different individuals of each species. Each group of living beings was ordered by some elements, the taxa, which divide each being according to a general grouping: species, genus, family, order and class.
Some scientific disciplines study living beings from a general perspective, that is, analyzing how they relate to each other and in turn to a specific environment (biodiversity or ecology are two branches of science that analyze this type of link) .
Main characteristics of living beings
In a very general way, one could speak of a series of common characteristics between the different living beings: each one of them is born from another being, they grow and develop until they die and have a series of basic needs (food, energy, light, water, etc). On the other hand, living beings live in a certain environment and adapt to it through a series of food chains that are related to each other.
The diversity of species that has survived has evolved through the mechanisms of natural selection. These mechanisms were described by the naturalist Charles Darwin, who spoke of adaptation to the environment and the struggle for survival as the two key factors in the evolution of different species.
