ucgatan at socrates-b.ucl.ac.uk
Tue Oct 7 09:49:04 EST 2003
On Thu, 2 Oct 2003, CyberLegend aka Jure Sah wrote:
> I have heard such that the organels have evolved seperately and were
> eventualy 'absorbed' into the cells and continued to live there.
This theory is known as 'serial endosymbiosis', and it only applies to the
mitochondrion and the chloroplast; some people suggest that eukaryotic
cilia and flagella (aka undulipodia) are also derived from bacteria, but
that is much less widely believed.
> I wonder how many hypotesys' are there that support the claim that the
> organels have evolved in the cells themselves?
That's an interesting question. I don't think there are any current
hypotheses which explain the origin of the mitochondrion or chloroplast
without reference to endosymbiosis. The killer evidence is that those
organelles have their own genomes, which are more similar to bacterial
than eukaryotic genomes; it's hard to see how such genomes could have
developed inside a eukaryotic cell.
Tom Anderson, MRC Laboratory of Molecular Cell Biology, UCL
Disclaimer: I really have no idea what i'm talking about.
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