Should Chloroplasts and Mitochondria be Considered Independent Organisms?

[FireBones]

I know that most people believe that chloroplasts and mitochondria evolved in eukaryotic cells by endosymbiosis, but has there been any push (or even any discussion) on whether they should actually be considered independent organisms living in symbiosis with the cell?

They fulfill most (if not all) the criteria for a "living thing."

My efforts at research through google ran up against a brick wall since the keywords I thought of all led me to the endosymbiosis theory itself rather than the question of classification.

 

[mazinse]

They are not considered living organisms in present cells because they lost a lot of genes necessary to survive independently and need host proteins to perform functions for them

 

[FireBones]

They are not considered living organisms in present cells because they lost a lot of genes necessary to survive independently and need host proteins to perform functions for them

Thanks, but I was under the impression that the ability to survive independently was not required so long as the entity could undergo metabolism (at all)...aren't there several bacteria that require this type of help as well?

 

[mazinse]

Thanks, but I was under the impression that the ability to survive independently was not required so long as the entity could undergo metabolism (at all)...aren't there several bacteria that require this type of help as well?

well that's an interesting way of putting it. if you really want to hit that gray area then yeah, think of them that way.

 

[LudusRex]

I can understand the curiosity and interest in considering chloroplasts and mitochondria as independent organisms living in symbiosis with the cell. However, the current scientific consensus is that these organelles are not considered separate organisms, but rather integral parts of eukaryotic cells.

The endosymbiosis theory, first proposed by Lynn Margulis in the 1960s, provides a well-supported explanation for the origin of chloroplasts and mitochondria in eukaryotic cells. It states that these organelles were originally free-living prokaryotic organisms that were engulfed by larger cells and over time developed a symbiotic relationship, eventually becoming permanent components of the cell.

While chloroplasts and mitochondria do possess some characteristics of living organisms, such as their own DNA and ability to reproduce, they are still dependent on the host cell for survival. They cannot exist independently and are unable to carry out all the functions necessary for life on their own.

Furthermore, the classification of an organism is based on a combination of factors, including genetic relatedness, physical structure, and ecological interactions. In the case of chloroplasts and mitochondria, their genetic makeup and structure are closely related to bacteria, but their ecological interactions are solely within the eukaryotic cell. Therefore, it is more accurate to classify them as organelles rather than independent organisms.

While there may be some debate or discussion on this topic in the scientific community, the current evidence and understanding supports the endosymbiosis theory and the classification of chloroplasts and mitochondria as organelles. As with any scientific theory, it is always open to further investigation and potential revisions as new evidence arises.