The Student Room Group
Reply 1
It's pretty widely accepted now, which makes it a little difficult to find counter-arguments - but I did find this, which might be useful - it suggests that mitochondria arose in a single eukaryotic ancestor at the same time as the nucleus rather than a series of endosymbiotic events. But it's really more of a variation on a theme than anything else...

There's also a short bit on Wikipedia: http://en.wikipedia.org/wiki/Endosymbiont_theory#Problems. The first argument against the theory is significantly better than the second though!
Jenski
I'm really interested in the endosymbiotic theory but it is only that- a theory.


Also research what a scientific theory is. Hopefully then you will get why people like me get annoyed when it is described as 'only' a theory.
Reply 3
Jenski
Ah. Sorry to have annoyed you ChemistBoy :confused: what do you mean exactly, what is a scientific theory?

Thanks MadNatSci for those links, very interesting.

I found out today that some people don't believe DNA is a helix..http://www.notahelix.com/, never heard of this idea before, I thought there was significant evidence (in the form of X-Ray crystal something...an analytical method) for it being a helix.


I think he's annoyed because you said something about the endosymbiotic theory being just a theory as if that makes some significant difference - all science is, is a collection of theories based on our current level of knowledge and understanding of how things work.
Reply 4
Jenski
I found out today that some people don't believe DNA is a helix..http://www.notahelix.com/, never heard of this idea before, I thought there was significant evidence (in the form of X-Ray crystal something...an analytical method) for it being a helix.

I don't know anything about that idea personally, but many of the greatest breakthroughs in science have come when someone challenged a long held belief that most took as fact. Bearing this in mind, I always try to keep an open mind with these things. :smile:
Reply 5
i find this whole thing confusing, how could a cell hace produced energy without the aid of a mitochondria
Reply 6
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(edited 6 years ago)
Reply 7
BouncyB
i find this whole thing confusing, how could a cell hace produced energy without the aid of a mitochondria


Mitochondria provide oxidative phosphorylation - there are plenty of other types of respiration.

If I remember correctly from last year, the original cell was a archaean methanogen? It then acquired the endosymbiont we call mitochondria. Hence this theory explains (as well as many other things) why modern archaeans are more closely related to eukaryotes than they are to bacteria.
Reply 8
Thankyou, i understand it now.
wildelectricity
all science is, is a collection of theories based on our current level of knowledge and understanding of how things work.


Not exactly insignificant though is it? A scientific theory is not just something that is based on our knowledge it provides a model for us based on the observed data - it is, in fact, our knowledge itself.

Of course the Oxygen catastrophe has to feature heavily in any discussion of endosymbiosis with respect to mitochondria.
Reply 10
ChemistBoy
Not exactly insignificant though is it? A scientific theory is not just something that is based on our knowledge it provides a model for us based on the observed data - it is, in fact, our knowledge itself.


Exactly - that's what I meant but it wasn't very clear.