Mitochondrial Evolution

[Nesti (Mark)]

I just learned something significant the other day (slow-poke LOL), that Mitochondria are not reproduced by cellular DNA...they are handed down from the mother (female egg linage); the Mitochondria in the male sperm are discarded.

For me, this suggests that way-back in history, two, perhaps even a few, cell types got together as a cooperative synergy (like bacteria in the gut) to gain an environmental advantage. This might have occurred before DNA itself even evolved...perhaps the structure and function of DNA could only have evolved because of the Mitochondria cooperative.

This also says to me that Mitochondria have evolved via proxy and not by direct influence and contact to the external environment. Kind of like 'The Dead Sea Scrolls' of the evolution of organic life.

I don't know why I didn't know this earlier, because that's pretty impressive!

[WarpSpider74 (Derek)]

When I studied Biology at Uni, it was accepted that Mitochondria and also Chloroplasts were independent primitive microorganisms which had become symbiotic to other microorganisms to the point where they became integrated structures. But yes, they reproduce themselves, and are not coded for in the cells DNA. Chloroplasts, btw, are similar to simple primitive cyanobacteria.

Oh and we must discuss that very tasty looking 4 (4.5?) metre glider you're holding there

[supernova1965 (Warren)]

I learned all that from watching Starwars when they found Anikan Skywalker Oh sorry that was Miticlorians

[bojan]

This is how we know that all humans came from Africa BTW..
We all have the same couple of mitochondrial signatures which came from our ancestors.
It is also possible to estimate the time elapsed since those times, based on known mutation rate of RNA in mitochondria.

[Nesti (Mark)]

Originally Posted by WarpSpider74

Oh and we must discuss that very tasty looking 4 (4.5?) metre glider you're holding there

Close...5m/6.5kg

[Nesti (Mark)]

Do their DNA genetically mutate like cellular DNA?

[bojan]

Originally Posted by Nesti

Do their DNA genetically mutate like cellular DNA?

I would say, why not?
Everything is exposed to cosmic rays, natural background radiation from Earth, chemical agents....
The mutation rate is probably faster, due to missing "repair" mechanisms that exist in cell nuclei during mitosis.

[Nesti (Mark)]

Originally Posted by bojan

I would say, why not?
Everything is exposed to cosmic rays, natural background radiation from Earth, chemical agents....
The mutation rate is probably faster, due to missing "repair" mechanisms that exist in cell nuclei during mitosis.

Quite right!...but talk about a sheltered upbringing.

[marki]

Yep the mitochondria located at the base of the tail in sperm only serve to provide energy for the long swim to the ova and are discarded with the rest of the sperm at the time of fertilisation. Outside of that the sperm only contribute half the genetic load and the centrioles. All the other mechanisms are present in the ova...this is why I always tell my female students if you marry a lazy bum you have to blame his mother . It is an interesting thought about mitochondrial DNA mutation as this can be used to determine maternity quite a long way back (I am led to believe right back to the start) so any mutation must be fairly mild in respect to gamet production I would think. Heres another tit bit for you Mark, did you know each Mitochondria contains exactly 12 hydrogen ions in solution?

Mark