Naked Science Forum
Life Sciences => Cells, Microbes & Viruses => Topic started by: ATremor on 05/01/2010 21:25:37
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How has this been determined? How far back did this symbiotic relationship go and why or how did we take the bacterium over? That fact that we functioned without them is boggling.
Thanks
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BTW, mitochondria have molecules all over their surface that spin constantly at about 100 to 200 revolutions per second. (Now I know why my ears ring constantly.)
They do??? which moles, I am intrigued! Are they uniqueto mitrochondria organelles??
P.S I am not ignoring the endosymbiosis, I will cover it if no one else does when I am not sleepy! But the above comment grabbed my attention.
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Thanks Dave that helps! I appreciate the extra tidbit as well. You know, my Army drill sergeant once insisted I had tinnitus. Ha could have blamed it on those damn mitochondria!
AT
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Some of the evidence for this includes that mitochondria have their own DNA, which looks a lot like a bacterial chromosome. Also the mitochondria have a double membrane, and the inner membrane looks a lot like the composition of bacterial membranes.
How organisms got along without them was anaerobic respiration, like fermentation that yeast carry out; it's very inefficient but worked for tiny microbes.
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How far back did this symbiotic relationship go ...
The oldest known fossilized prokaryotes were laid down approximately 3.5 billion years ago, only about 1 billion years after the formation of the Earth's crust... Eukaryotes (http://en.wikipedia.org/wiki/Eukaryote) only appear in the fossil record later, and may have formed from endosymbiosis of multiple prokaryote ancestors. The oldest known fossil eukaryotes are about 1.7 billion years old. However, some genetic evidence suggests eukaryotes appeared as early as 3 billion years ago.
http://en.wikipedia.org/wiki/Prokaryote#Evolution_of_prokaryotes
That fact that we functioned without them is boggling.
Humans were never "without them".