Revisão crítica de hipóteses sobre a origem da mitocôndria

sábado, setembro 02, 2017

Breath-giving cooperation: critical review of origin of mitochondria hypotheses

Major unanswered questions point to the importance of early ecology

István Zachar and Eörs Szathmáry

Biology Direct201712:19 © The Author(s). 2017 ReadCube 

Received: 14 March 2017Accepted: 20 July 2017Published: 14 August 2017

Source/Fonte: Georgia Tech Biology


The origin of mitochondria is a unique and hard evolutionary problem, embedded within the origin of eukaryotes. The puzzle is challenging due to the egalitarian nature of the transition where lower-level units took over energy metabolism. Contending theories widely disagree on ancestral partners, initial conditions and unfolding of events. There are many open questions but there is no comparative examination of hypotheses. We have specified twelve questions about the observable facts and hidden processes leading to the establishment of the endosymbiont that a valid hypothesis must address. We have objectively compared contending hypotheses under these questions to find the most plausible course of events and to draw insight on missing pieces of the puzzle. Since endosymbiosis borders evolution and ecology, and since a realistic theory has to comply with both domains’ constraints, the conclusion is that the most important aspect to clarify is the initial ecological relationship of partners. Metabolic benefits are largely irrelevant at this initial phase, where ecological costs could be more disruptive. There is no single theory capable of answering all questions indicating a severe lack of ecological considerations. A new theory, compliant with recent phylogenomic results, should adhere to these criteria.

Reviewers: This article was reviewed by Michael W. Gray, William F. Martin and Purificación López-García.


Mitochondria Endosymbiosis Eukaryogenesis Ecology Evolution Metabolism Parasitism Major transition

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