4 ms·

So what is it that they have in place of mitochondiria? A fascinating book "Power, Sex, Suicide: Mitochondria and the Meaning of Life" (http://www.amazon.com/P

by Evgeny 17y ago

So what is it that they have in place of mitochondiria? A fascinating book "Power, Sex, Suicide: Mitochondria and the Meaning of Life" (http://www.amazon.com/Power-Sex-Suicide-Mitochondria-Meaning/dp/0199205647 http://www.amazon.com/Power-Sex-Suicide-Mitochondria-Meaning...) suggested that the multicellullar organisms on Earth evolved only once, when the symbiotic relationship between two types of bacteria was formed - one of them became "host", and the other became mitochondria and specialized for energy production. The book suggests that the conditions for this to happen were very unusual and are unlikely to ever happen again. It does even suggest that this may mean that life in the Universe, more complicated that single-cell organisms, is very unlikely to evolve. If eukaryotes evolved more than once, then there's some more hope for extraterrestrial life I suppose ...

eru 17y ago
> If eukaryotes evolved more than once, then there's some more hope for extraterrestrial life I suppose ... Wouldn't you call extraterrestrial bacteria `life'?
- netcan 17y ago
  Well, most people think multicellular when they get excited about life because multicellular is how earth life gets complex. To that end eliminating flukes that happen only once is important.
  - eru 17y ago
    OK. I am not that discriminating. (Actually, Archae and Bacteria are much more interesting too me.)
etal 17y ago
They use hydrogenosomes, or something similar, instead: http://en.wikipedia.org/wiki/Hydrogenosome http://en.wikipedia.org/wiki/Hydrogenosome It looks like the metabolic reaction is somewhat similar to the aerobic one used by mitochondria, but uses hydrogen ions instead of oxygen molecules. Hydrogenosomes may or may not be evolutionarily related to mitochondria. Here's the original journal article (open access): http://www.biomedcentral.com/1741-7007/8/30/abstract http://www.biomedcentral.com/1741-7007/8/30/abstract

by Evgeny 17y ago

eru 17y ago

> If eukaryotes evolved more than once, then there's some more hope for extraterrestrial life I suppose ... Wouldn't you call extraterrestrial bacteria `life'?

netcan 17y ago
Well, most people think multicellular when they get excited about life because multicellular is how earth life gets complex. To that end eliminating flukes that happen only once is important.
- eru 17y ago
  OK. I am not that discriminating. (Actually, Archae and Bacteria are much more interesting too me.)

etal 17y ago

They use hydrogenosomes, or something similar, instead: http://en.wikipedia.org/wiki/Hydrogenosome http://en.wikipedia.org/wiki/Hydrogenosome It looks like the metabolic reaction is somewhat similar to the aerobic one used by mitochondria, but uses hydrogen ions instead of oxygen molecules. Hydrogenosomes may or may not be evolutionarily related to mitochondria. Here's the original journal article (open access): http://www.biomedcentral.com/1741-7007/8/30/abstract http://www.biomedcentral.com/1741-7007/8/30/abstract