Difference Between Endosymbiosis and Symbiosis

The key difference between endosymbiosis and symbiosis is that endosymbiosis is a theory that describes how mitochondria and chloroplasts entered eukaryotic cells while symbiosis is a long term interaction existing between two different living species.

Organisms in an ecosystem interact with each other in different ways. Symbiosis is an interaction that exists between two different species living together. Some interactions benefit both parties, while some interactions remain neutral. However, some other interactions are harmful to one party, especially to host organism, while the other party receives benefits at the expense of the host. We can see all these types of interactions in an ecosystem. However, these kinds of interactions are vital for the stability of an ecosystem. Endosymbiosis, on the other hand, is a theory that explains the origin of the eukaryotic cell from a prokaryotic cell.

CONTENTS

1. Overview and Key Difference
2. What is Endosymbiosis 
3. What is Symbiosis
4. Similarities Between Endosymbiosis and Symbiosis
5. Side by Side Comparison – Endosymbiosis vs Symbiosis in Tabular Form
6. Summary

What is Endosymbiosis?

Endosymbiosis is a hypothesized process that explains the origin of the eukaryotic cell from a prokaryotic cell. It is one of the most important events associated with evolution. Hence, it is an accepted theory in biology. Endosymbiosis theory describes the mechanism by which mitochondria and chloroplasts entered eukaryotic cells. These two organelles have their own DNA. Therefore, scientists believe that mitochondria have originated in eukaryotic cells from autotrophic alphaproteobacteria via endosymbiosis. It is a result of a symbiotic relationship between a primitive eukaryotic cell and an autotrophic bacterium. The primitive eukaryotic cell has engulfed the bacterium, and their symbiotic relationship has led to the origin of mitochondria in eukaryotic cells.

On the other hand, chloroplasts have originated in plant cells from cyanobacteria through endosymbiosis. A primitive eukaryotic cell with mitochondria has engulfed a cyanobacterium, and that has led to the origin of chloroplasts inside the photosynthetic eukaryotic cells. Therefore, endosymbiotic theory scientifically explains how mitochondria and chloroplasts established inside the eukaryotic cells from bacteria.

What is Symbiosis?

Symbiosis is a long term association between two different species of organisms that live together. There are three types of symbiotic relationships as parasitism, mutualism and commensalism. Mutualism brings benefits for both partners that are in the association, unlike the other two types. Lichen and mycorrhizae are two common examples of mutualistic associations. Commensalism is a type of symbiotic interaction between two species in which one species receives benefits such as nutrition, locomotion, shelter, support, and food scraps, etc., while the second species is not benefited or harmed. Commensal is the party benefited by the interaction. Examples for commensalism are biting lice, fleas, and louse that feed harmlessly on the feathers of birds.

Parasitism is a non-mutual relationship between two species, where one species benefits at the expense of the other. In this relationship, the parasite gets benefits at the expense of the host organism. Therefore, parasites are the organisms that live in or on another organism to derive nutrients. Parasites cause damages to host organisms and interfere with the metabolic functions as well. A parasite is always dependent on the host for its survival. It cannot survive independently.

What are the Similarities Between Endosymbiosis and Symbiosis?

• Endosymbiosis happened due to the symbiotic relationship between a primitive eukaryotic cell and an autotrophic bacterium.
• Both endosymbiosis and symbiosis explain the interaction between the two partners.
• They are evolutionary important concepts.

What is the Difference Between Endosymbiosis and Symbiosis?

Endosymbiosis explains the mechanisms by which mitochondria and chloroplasts entered into eukaryotic cells from prokaryotic cells. In contrast, symbiosis is a long term interaction existing between two different species. So, this is the key difference between endosymbiosis and symbiosis.

Summary – Endosymbiosis vs Symbiosis

In summary, the endosymbiosis is the theory that explains the origin of mitochondria and chloroplasts in the eukaryotic cells. On the other hand, symbiosis is an interaction between two different species that are living together. Mutualism, commensalism and parasitism are the three types of symbiosis. This summarizes the difference between endosymbiosis and symbiosis.

Reference:

1. K.Aanena, Duur, and AbstractSymbiogenesis. “Symbiogenesis: Beyond the Endosymbiosis Theory?”Journal of Theoretical Biology, Academic Press, 18 Aug. 2017, Available here.
2. “Symbiosis – Definition, Types and Examples.” Biology Dictionary, 8 Apr. 2019, Available here.

Image Courtesy:

1. “Endosymbiosis” By Signbrowser – Own work (CC0) via Commons Wikimedia
2. “2046695” (CC0) via Pixabay