The levels of biological organization are what shows to what extent, in biology, living beings do not exist in an isolated and independent manner, but are in constant interaction with each other.

Specifically, the levels of biological organization are a hierarchy of categories that go from the micro to the macro (and vice versa), showing us different dimensions of analysis of living beings. These levels are: individual, population, community, ecosystem, biosphere and biome. In this article we will see their characteristics.

The levels of ecological organization

When studying nature, we must choose a level of analysis to focus on , that is, a type of natural phenomenon that will force us to pay attention to what is happening on a certain scale, and not on another, leaving aside everything else.

The levels of biological organization are the classification in which we divide different elements to be studied, depending on whether they are more concrete and local or more general and global . It is applied in sciences related to the study of nature and living beings, such as zoology, ethology, anthropology, etc.

In this way, the level of analysis of the community is broader and more general than that of the population, but less than that of the ecosystem, and therefore will lead us to study phenomena that we could not find at more concrete or more global levels.

Thus, this hierarchical organization of categories allows us to know, when selecting one of them, to what extent we are close to the scale of individuals or biomes, the two extremes of the classification of the levels of ecological organization.
Let us see in more detail what each of these categories consists of.

1. Individual

This is the basic unit, the most local and concrete level within the levels of ecological organization.

These are living beings, not necessarily animals, which are often functional and can react to stimuli or sometimes even carry out complex actions. If they are only examined for physical or anatomical characteristics, they do not need to be alive.

At this level of study it is possible to investigate elements such as morphology, behaviour, physiology , etc.

Furthermore, starting from this level of ecological organization, it is possible to establish theories and hypotheses about things that go beyond the individual himself, such as which species he belongs to, what needs his body adaptations respond to, etc.

2. Population

The population is the level of ecological organization defined by a group of individuals of the same species that live together or are organized together to survive at a given time and in a given place (on a rather local scale, given that they share the same space).

It should be borne in mind that even within a single species there is a certain diversity in terms of genotypes (genes) and phenotypes (traits expressed in body or behavioural characteristics), so it is not assumed that a population is a succession of identical individuals. This enriches this level of study, because there are always phenomena to be investigated that are not present where we only look at one individual.

For example, aspects that we can investigate by focusing on the population level are the cooperation between the members of a family or a tribe , the expulsion of males when they reach puberty, the way in which food is shared, the internal struggles for the leadership of the group, etc.

3. Community

The community is the level formed by a group of populations of different species, and which interact with each other in a specific area. Here life forms of all phyla are included: animals, plants, fungi, bacteria, etc .

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Moreover, it is this constant interaction between various forms of life that makes them able to exist, because it creates a biological balance that provides stability and sustenance to most populations and individuals.

From this level of ecological organization, processes such as predation, parasitism, symbiosis, etc. can be studied .

4. Ecosystem

The ecosystem is a type of extensive physical environment characterized by phenomena that go beyond the existence of living beings, such as temperature, the level of luminosity, rainfall , geographical features, etc. They are also characterized by the community of living beings that they shelter, which may vary slightly depending on which part of the ecosystem we are in, given that this is not totally homogeneous and regular.

Thus, an ecosystem has two fundamental components: an abiotic element, which includes non-organic elements, and a biotic element, which includes living beings.

The combination of these two halves forms an environment with a relatively autonomous dynamic of existence, in which to maintain this balance does not require much interference from elements outside the ecosystem .

At this level of ecological organization, the impact of pollution on an area, desertification processes, loss of biodiversity caused by drought, etc. can be studied.

5. Biome

A biome is a category that encompasses several ecosystems that present some similarities among them and that in many occasions are in physical contact with each other (although this is not a fundamental requirement to establish the existence of a biome, given that sometimes there are jeoographic features that “split” a biome).

Thus, the biome is a type of landscape that can be identified by presenting certain uniformity in terms of its larger forms of life: normally, animals and plants.

In addition, the extent of the biomes is usually large, on the scale of a medium or large country (although it is independent of state and national boundaries); they are usually easily identifiable on a world map (although it costs more for underwater biomes).

If we look at this level of analysis, it is possible to study phenomena such as the melting of the poles, the deforestation of large areas that threatens mass extinction of species, etc.

6. Biosphere

The biosphere is the largest level of ecological organization, and covers the entire planet , composed of the fit of the different biomes.

On the other hand, the biosphere is made up of three components: the listosphere, composed of all the regions where the earth gives relief to the earth’s crust; the atmosphere, composed of the ozone layer that covers the entire earth’s crust; and the hydrosphere, composed of the large masses of water that are distributed throughout the earth’s crust, regardless of whether they are visible by satellite or not.

If we focus on this scale, we can study the consequences of climate change almost in its entirety, as well as meteorology , the movement of tectonic plates, etc.

Bibliographic references:

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