Ecological Population of Organisms

Ecological population of organisms
Ecological population of organisms

Ecological population of organisms deals with the dynamics of species population. It explains how and why a population changes over time.

It also deals with the various factors affecting population growth, rates of survival and reproduction, and risk of extinction.

An ecosystem consists of all the organisms and their interacting physical environment. It has the following two factors:

  •  Biotic factors e.g., people, plants, animals, fungi, and bacteria.
  •  Abiotic factors e.g.,  Light, radiation, temperature, water, chemicals, gasses, wind, and soil.

These factors are interlinked with each other. Removing one factor leads to catastrophic effects on the rest of the ecosystem and disrupts homeostasis.

Most important factor that determines where major ecosystem are located on the globe is climate. It is average weather in a particular area over a long period of time.

Climate change has become one of the major problems affecting the ecological population. 

Table of Contents

Which of the following groups of organisms are or are not  populations?

The following groups of organisms are populations:

  • European wolves.
  • Mountain gorillas.
  • Oak trees in a forest.
  • Human population of the USA.

The following groups of organisms are not populations:

  •  A spider and trapped flies in a web
  •  Earthworm that lives in grassland along with other arthropods
  •  All plants in a forest.
groups of organisms are or are not  populations?
Groups of populations are organisms

A population has to be of the same species.

If we compare a group of people at a football game and birds in a forest, the organism most likely to belong to the same species will be ‘people’ at the football game, not birds in a forest. 

Humans belong to the same species and they have the capability to interbreed among themselves whereas there are multiple species of bird in a forest and not all of them are capable of interbreeding with each other.

The above mentioned differences clarify the definition of population which is “a group of individuals that belong to the same species and live in the same area”.

Ecological population definition

Ecological population is defined as the study of the processes that affect the distribution and abundance of an organism. It also looks at how these relate to the environment or ecosystem and their ecological relationships.

Ecological population definition
Ecological population

For example how populations and communities affect one another.

In an ecosystem, communities evolve to have greater biomass and species richness in a process called succession. It is basically the change in the species structure of an ecological population over time. 

Ecology plays a major role in understanding the knowledge of the interdependence between people and nature and this phrase best describes the study of ecology. 

How can scientists compare two different populations

Scientists can compare two different populations to analyze and test two populations. For this purpose, they take out random samples from each of two populations.

Scientists then examine these samples individually and try to find how each sample is different and unique from another sample.

The sample of two groups is independent, the common use of this comparison between two different populations is an experimental response to two different populations.

Population definition environmental science

The definition of population in environmental science is a group of the same species living and interbreeding in a specific area.

Population definition environmental science
Population definition environmental science

Different populations together make a biological community of organisms and their environment and the region in which populations interact with each other is known as the ecosystem.

Three important characteristics of the population are as follows

  • Density
  • Growth rate
  • Distribution

The density of a population means the number of organisms in a specific area. For example, 100 pigeons living in a square mile.

The growth rate of a population is defined as the rate at which the population increases. It depends upon the number of deaths, the number of births, and the number of organisms emigrating or immigrating into a region.

Population definition environmental science

Distribution means how organisms are distributed in space at a given time.

Population living things

Population of living things is an estimate of the number of Earth’s current species. It ranges from 10 million to 14 million. There is a variety of organisms that inhabit the earth and each one of them has been categorized into different groups.

The organisms in a population are distributed into the following patterns:

  • Uniform pattern.
  • Random pattern.
  • Clumped pattern.

Uniform means that the population is evenly spaced, random indicates random spacing, and clumped means that the population is distributed in clusters.

Population of living things

Population size of living things is altered by many factors, the most important of which is genetic variations. It is caused by mutation in genes, and recombination or reshuffling of genes during meiosis. It is an important force in evolution. 


Which factor explains a uniform distribution of individuals in a population?

The factor which explains a uniform distribution of individuals in a population is territoriality.

Which group would be an ecological population of organisms?

The group that is an ecological population of organisms is all chipmunks in a woodlot.