Principles of ecology

Published on 28 Oct 2025

The major principles of ecology depend upon the study of interactions between organisms and their environment. These principles include:

• Adaptation: The appearance or behaviour or structure or mode of life of an organism that allows it to survive in a particular environment.

• Example: In aquatic flowering plants, there is an absence of wood formation and a highly reduced root system.

• Variation: It can be defined as any difference between the individuals in a species or group of organisms of a species. They are induced by changes in genetic makeup due to the addition or deletion of certain genes.

• Example: The difference in skin colour, eye colour, and blood type among different ethnic groups represents the variation within the human species.

• Interdependence: The survival of an organism depends upon the relationship of this organism with other species and their environment.

• Example: Bees help in pollinating flowers, and, in turn, flowers provide bees with nectar.

• Speciation: It is how a new kind of plant or animal species is created. This occurs when a group within a species separates from other members of its species and develops its own unique characteristics.

• Example: Galapagos finches living on different islands in the Galapagos archipelago have distinct morphology.

• Mutation: It is a change in the structure of a gene, the unit of heredity. It can be considered as the engine of evolution that generates the genetic variation on which the evolutionary process depends.

• Example: Animals born with extra body parts, such as two-headed snakes and four-legged ducks.

• Natural selection: It is a mechanism of evolution in which organisms that are more adapted to their environment have higher chances to survive and pass on the genes that aided their success.

• Example: Evolving long necks have enabled giraffes to feed on leaves that others can't reach, giving them a competitive advantage.

• Evolution: It is the process by which species adapt over time in response to their changing environment. This can be induced by geographical phenomena like continental drift, glacial cycles, etc.

• Example: Human evolution

• Extinction: It is the complete disappearance of a species from Earth.

• Example: Extinction of Woolly mammoth

Tags:
Environment

Keywords:
Principles of ecology ecology Adaptation variation Interdependence speciation Mutation natural selection Evolution extinction Woolly mammoth Galapagos finches

Syllabus:
General Studies Paper 3

Topics:
Environment and Climate Change