Ecology and Environment for UPSC

Ecology and Environment for UPSC


  • It is derived from 2 words –
    o “Okios” means house or environment
    o “logos” meaning the study of.
  • Ecology is the scientific analysis and study of interactions among organisms and their
  • It is not synonymous to Environment.
  • It is closely related to evolutionary biology, genetics, and ethology.
  • This term was first given by Biologist Hackle in 1869.
  • Ancient Indian texts also throw light on ecological principles. Vedas, Samhitas, Brahmanas, Aryankas-Upanishads contain many references to ecological concepts.
  • Charak Samhita (a Sanskrit text on Ayurveda) and Sushruta Samhita (an ancient Sanskrit text on medicine and surgery) show that even earlier also people have a good understanding of plant and animal ecology.


  • When we say environment it simply means surroundings.
  • The environment is biotic (living organisms) and abiotic (non-living organisms) surrounding an organism or population and also includes the factors that have an influence on their survival, development, and evolution.
  • The environment is our basic life support system. It provides the air we breathe, the water we drink, the food we eat and the land where we live.

Relationship between an organism and environment

  • The relationship is highly complex
  • Each organism’s environment consists of other organisms as well.
  • An organism cannot survive without interacting with other organisms.
  • Everything which is needed for our survival or interaction forms part of the environment.
  • The environment is dynamic and not static.
  • For example – environment of a fish in a pond.

 External environment

  • Abiotic components – temperature, light, water with nutrients rich, oxygen dissolved. 
  • Biotic components – Planktons, aquatic plants, and animals.

Internal environment

  • Outer body surface
  • Stable than external environment but not absolutely constant. Injury etc. upsets the internal environment.
  • If a marine fish is transferred to the freshwater environment, it will not be able to survive.


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This Post Has 2 Comments

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    valuable expeгience on the topic of unpredicted emⲟtіons.

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