That's a popular theory... it's not the only theory though... nor has it been proven....

Once again quoting wikipeida....

• Neither mitochondria nor plastids can survive in oxygen or outside the cell, having lost many essential genes required for survival. The standard counterargument points to the large timespan that the mitochondria/plastids have co-existed with their hosts. In this view, genes and systems which were no longer necessary were simply deleted, or in many cases, transferred into the host genome instead. (In fact these transfers constitute an important way for the host cell to regulate plastid or mitochondrial activity.)

• The transfer of genes from mitochondria and plastids to the “host genome” or cell nucleus raises a further problem: why were all genes not transferred? In other words, why do any genes at all remain in mitochondria and plastids? This problem is addressed by the CoRR Hypothesis which proposes that genes and respiratory chain proteins are Co-located for Redox Regulation.

• A large cell, especially one equipped for phagocytosis, has vast energetic requirements, which cannot be achieved without the internalisation of energy production (due to the decrease in the surface area to volume ratio as size increases). This implies that, for the cell to gain mitochondria, it could not have been a primitive eukaryote, but instead a prokaryotic cell. This in turn implies that the emergence of the eukaryotes and the formation of mitochondria were achieved simultaneously.

• Genetic analysis of small eukaryotes that lack mitochondria shows that they all still retain genes for mitochondrial proteins. This implies that all these eukaryotes once had mitochondria. This objection can be answered if, as suggested above, the origin of the eukaryotes coincided with the formation of mitochondria.

There are hypothisis to explain it... but nothing set.

There has to be a different better example for evolution... a Theory can't be based on hypothisises.

I think looking futher along the line is a more likely way to find what makes it an accepted fact.

Okay, see? You keep changing the question around. It's kind of hard to have a lot of diversity if you only have one cell and reproduce asexually. Does that answer your question?

 You Sir ask some good questions.

You should still modify them a lil IMO, to a broader sense. To look from a broader perspective than to just narrow yourself into thinking "why is the cellcore so important".

Because that would need proof that says that "inventing" the cellcore is an extremely unlikely event in organisms.
(but I have never ever heard anyone claim that)

Now in my opinion one of the most hard things to refute, evidence of evolution over an amazingly short timescales in recent times.

http://www.sciencedaily.com/releases/2008/04/080417112433.htm

@Kasz: Absolutely, it is still just a hypothesis, but even the fact that you have something as strange as organelles in a bacteria that have their own set of DNA almost intuitively suggests that they were once their own separate bacteria. I have yet to see an explanation that makes as much sense given the nature of mitochondria/chloroplasts and bacteria themselves.

That is a perfectly fine position to have and there isn't anything wrong with it, but faulting all of evolution theory based on the reasoning that bacteria do not ever evolve into multi-celled organisms is being a little narrow minded.  I thought there was some evidence proving that multi-celled bacteria couldn't exist based on some traits that exist in bacteria.

I believe in Evolution... so just playing devils advocate but...

What about helpful DNA Damage?

Rather then like with humans where it is negative... the DNA damage actually helped those parts of the bacteria... and as such the DNA damage was helpful?

After all Cancer Cells are genetically different from other cells.  If we were born with cancer one could come to the same conclusion you did?

Additionally there are people with two types of DNA.

Some are due to inheriting their wayward twins DNA and others happen due to errors in replication.

It could of just been the cause of a replication error.

Im not dodging or anything like that. Perhaps Im clumsy in my presentation but thats all.

 I'd like to object to your claim when you say "it's kind of hard to have a lot of diversity" about bacteria, when people argue that "yeah, it was perfectly logical and likely that amino acids started getting linked together and eventually became all life forms we know of", and they did it step bby step - in the next step these amino acid strings formed self replicating machines and so on (as the first steps of how life started, the early "pre-life" that now is extinct, from the special conditions of a young earth).

Just take a look at the bacteria pool - that mass of potential to "become" stuff is vastly bigger than the self-replicating primitive machines that then became the first cells.


I mean, the possibility for 100s of billions of billions of bacteria to become any other "species" should be a lot more likely, during 500 million years, than for the "primordial soup" amino acids to become the first cell in the first place.

Life should have branched of from the prokaryotic tree so much more.

Evolution

 Just saying if u missed it: im not saying bacteria doesn't evolve at all. Im asking why they are stuck. (yes, IMO "them being stuck" is a pretty good description to point at the essence of the problem, even if you can obviously easily dispute it by saying that there's a myriad of variety between bacteria)