Magical mitochondria: related to inventive mechanism? (Introduction)

by David Turell , Friday, October 17, 2014, 16:22 (3478 days ago)
edited by David Turell, Friday, October 17, 2014, 16:27

Shown by Lynn Margulis to be encapsulated from bacteria into cells to provide the energy needed to produce complex animals. This a study of the possible origin. Is this how an inventive mechanism would work?:-"The study appears this week in the online journal PLOS One, published by the Public Library of Science. It provides an alternative theory to two current theories of how simple bacterial cells were swallowed up by host cells and ultimately became mitochondria, the "powerhouse" organelles within virtually all eukaryotic cells - animal and plant cells that contain a nucleus and other features. Mitochondria power the cells by providing them with adenosine triphosphate, or ATP, considered by biologists to be the energy currency of life."-http://medicalxpress.com/news/2014-10-upends-current-theories-mitochondria-began.html-Actual abstract and whole article:-http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0110685-Conclusion: "A recent systematic survey of bacterial symbiosis has shown that mutualisms can originate either directly from environmental free-living bacteria or from intracellular parasites [49]. A key difference between these two evolutionary routes is that to initiate symbiosis, free-living bacteria need to offer immediate benefits to the host while intracellular parasitic bacteria do not [50]. Our results suggest that mitochondria most likely originated from an obligate intracellular parasite and not from a free-living bacterium. This has important implications for our understanding of the origin of mitochondria. It implies that at the beginning of the endosymbiosis, the bacterial symbiont provided no benefits whatsoever to the host. Therefore we argue that the benefits proposed by various hypotheses (e.g., oxygen scavenger hypothesis and hydrogen hypothesis) are irrelevant in explaining the establishment of the initial symbiosis. Instead, it might be more appropriate to apply them to explain the transition of mitochondria from a parasite to a mutualistic organelle at a later stage."