Of course they could not, as they exist now, but then this is a strawman. The endosymbiotic theory holds that the ancestors of mitochondria were intially engulfed as free living bacteria (there are plently of contemporary examples of this, btw) and then, over time, became symbiotic with their host, possibly starting out as parasites (there are also modern example of this happening), and then, again over time, developed the tight, integrated and obligate relationship we see today.
Fact remains that regardless of the rhetoric the production of ATP is necessary. The endosymbiotic theory has absolutely no factual evidence behind it as you admit above. For it to be true both the prior ATP mechanism had to have dissappeared without a trace in all these organisms, the new parasitic organisms had to have reduced themselves (all of them the same way! in all organisms!) to unviable organs, and all examples of these original parasites must have dissappeared from everywhere. All of this shows my point quite well - that this is garbage, it is fact-free pseudo-science and there is no evidence for it except the need of evolution to make up a story to justify its theory in this very important and essential part of living organisms.
So what this discussion comes down to (which you will strenuously deny) is that my original statement is absolutely true - mitochondria and chloroplasts are original organs of eukaryotic organisms, just like many other organs in these organisms are original with them and cannot be claimed to have arisen as parasites. There is no evidence otherwise and the 'endoplasmic theory' is just more evolutionist made up nonsense.
To further complicate the problems that mitochondria create for evolutionists it should be noted that unlike other DNA, the genetic code of mitochondrial DNA is not only different from that of normal DNA but it also differs between species! Fredrick Sanger 1980 Nobel Lecture. So just more proof that this was not a parasite.
Huh? I could be wrong, being far from expert on these matters, but as far as I know all eucaryotes that lack mitchondria only produce ATP anaerobically, nor am I aware of any evidence that eucaryotes ever had the ability to produce ATP aerobically apart from mitochondria. And of course eucaryotes all retain the ability to produce ATP anaerobically. So what it is that you are saying "had to have dissappeared without a trace" is a complete mystery to me.
Yes. It comes down to this bald assertion on your part. That's what I've been saying!