What precisely is ecology? How does it differ from biology? Because I never studied biology after high school, please explain as if I were 10 years old. I only know that ecology is a subset of biology

I tried some dictionaries but they didn't adequately discriminate. I tried to find an explanation from a scientist: the following appears to claim that only ecology concerns some organism's external interactions with other entities? But how? Biology must also? For example, suppose that someone studies prions' interactions with humans, and not just prions. Then this is biology, not ecology?

Source: by Matthew Fraser, PhD Candidate (Marine Ecology) at University of Western Australia

So what makes us fully fledged marine ecologist different from our biologist counterparts? Well, I think that marine ecology is even cooler than marine biology because as marine ecologists we link what we know about the biology of a given species with other plants/animals and the environment as well. [...]

If we were splitting hairs, ecology is technically a form of biology, but I felt the need to write this post given how passionately I see some researchers stating that they are in one camp or another. [...] But as an ecologist (albeit a biased one!) what gets me excited isn’t just finding out how the amazing plants and animals we find in the ocean work, but how they interact with each other and their environment, explaining why we see certain species in some places and not others!

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    $\begingroup$ Does the Wikipedia article not adequately define ecology for you? "Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy" whereas ecology "is the scientific analysis and study of interactions among organisms and their environment." What other information are you looking for? $\endgroup$
    – MattDMo
    May 30, 2015 at 20:28
  • $\begingroup$ @MattDMo Sadly, no. The definition there for ecology also applies to biology; biology also concerns interactions among organisms and their environment. $\endgroup$
    – user4466
    May 30, 2015 at 20:30
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    $\begingroup$ Ecology is a subset of biology, and also includes some elements of other disciplines as well, including earth science. "Biology" is an extremely broad term encompassing a huge number of sub-specialties. I urge you to read the entire article I linked, it explains the field of ecology quite well. $\endgroup$
    – MattDMo
    May 30, 2015 at 20:34
  • $\begingroup$ The definition of ecology fits within the definition of biology because it is a field of biology. There is no clear cut between ecology and biology, it's like trying to find a clear separation between physics and astrophysics, sharks and fish, humans and mammals, our sun and stars - they are just definitions, ecology satisfies the criteria to be defined as biology but not all biology is ecology. $\endgroup$
    – rg255
    Jun 1, 2015 at 5:54
  • $\begingroup$ Some might argue that, given its interdisciplinary nature, ecology does not fit entirely within biology. Think human cyborgs and mammals. $\endgroup$
    – Gossar
    Jun 3, 2015 at 3:19

2 Answers 2


Ecology has two meanings. The popular and the scientific meaning.

Ecology: the popular definition: Here the term ecology is probably quite poorly defined. To my gut feeling, the concept relates to the concept of global change. It encompass many fields such as biology (ecology (in the scientific sense), evolutionary biology and conservation biology especially), ethics and moral, politics, meteorology, public policy, ...

Ecology: the scientific definition: Ecology is a subfield of biology and earth sciences that studies interactions among organisms and their environment. interaction is an important word here.

Biology has a much broader meaning. Biology is the science that studies life. Biology studies the structure, the ecology (impact on their surrounding), the evolution, development biochemical processes, etc.. of living things. Biology is a very big field of science. A researcher in biology will probably not really consider him/herself as a biologist but rather as a molecular geneticist, a neurologist, a epidemiologist, a plant physiologist, a biochemist, a bioinformatician, a system biologist, etc.. For example, I would appreciate to consider myself as a population geneticist rather than as a biologist as there are many fields of biology I know nothing about. For example, I am a pretty bad naturalist.

In short, ecology is to biology what optics is to mechanics is to physics. Some people may not like this comparison as mechanics might take a larger part of physics that what ecology does to biology. Earth scientists may not like this comparison as well, as they are part of ecology without necessarily feeling like being part of biology. But anyway.

From the text you cite

[..] as an ecologist [..] what gets me excited isn’t just finding out how the amazing plants and animals we find in the ocean work, but how they interact with each other and their environment [..]

It shows that indeed ecologist are interested in the interaction between organisms and between organisms and their abiotic environment. Matthew Fraser says "he's not only interested in how they work". 'How they work' is obviously an extremely inaccurate sentence. A less misleading reformulation would be: I am not interested in everything about the biology of marine animals, "I am especially interested in how animals interact with each other and how they interact with the environment", but obviously that is less exciting for the reader. The goal of Matthew I guess was to create the interest and the excitation of the reader (or audience) on ecology and for this purpose he kinda implied as ecology being more than biology, while ecology is only a subfield of biology.

For more information, wikipedia is your friend!


Yes, there is overlap and the line is rather fuzzy. As a distinct discipline within biology, ecology is a fairly young science. The word itself did not exist until 1866.

Biology is focused on living things usually at the organismal level or smaller (organs, cells, proteins, biochemistry, etc.) Generally when biologists consider abiotic factors, it is how those factors affect an organism (water, light, air needed to live). Ecology usually looks at the organismal level and higher (species, population, community, etc.). Ecologists also study the two-way interaction between biotic and abiotic factors, how organisms change their habitat, and how the habitat changes the population.

Modern biology is such a large subject that most scientists will specialize in a sub-field such as botany, zoology, genetics, etc. One of those sub-fields is ecology, but ecology is also interdisciplinary and draws from fields beyond biology like chemistry, geology, climatology, etc.

A biologist might study one or two species of fish in a lake and the plants they feed on. An ecologist might study the lake itself, how the water got there, how an invasive species is changing the lake's biodiversity.


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