“It’s been shown that mitochondria (the parts of the cell that process energy) had their origin in cyanobacteria.”
You mean it’s been observed in the lab under controlled conditions?
You mean it’s been observed in the lab under controlled conditions?
My sincere apologies -- I got the bacteria species wrong! The theory is that mitochondria originated from Rickettsiales-like paleobacteria. See Endosymbiotic Theory for details. My porous memory garbled the story: chloroplasts (the organelles in green plant cells that do photosynthesis) originated in cyanobacteria, which also contain chlorophyll. (Details: Photosynthesis.)
Anyway, the origin of mitochondria is an event that happened billions of years ago. But here's the evidence: As you might know, the DNA of eukaryotic cells (cells with nuclei) form long chains, while the DNA of bacteria comes in closed loops called plasmids. Mitochondria happen to have their own DNA, separate from the DNA in the nucleus of the eukaryotic cell. Their DNA turns out to be a closed loop, just like that of bacteria. There are other features of mitochondria that are bacteria-like, in fact, quite similar to the one particular type of bacteria mentioned above. I don't remember the details. I read about this in a lovely book, Microcosmos: Four Billion Years of Microbial Evolution, co-authored by Lynn Margulis, who is credited with doing a lot of the work towards establishing the bacterial origin of mitochondria.
Now you ask about lab experiments. As I mentioned, the origins of mitchondria or chloroplasts were long ago. But interesting experiments have been done showing how a single-celled organism (an amoeba) could be infected with a bacteria species, and the bacteria get transmitted to the amoeba's descendents. The interesting thing about the experiment is that over time, the amoebae became dependent upon the bacteria, relying on the bacteria for certain biochemical functions and losing the ability to do these functions on their own. (This was shown by surgical removal of the bacteria from the amoeba.) In other words, the amoeba had formed a successful symbiotic relationship with the bacteria. Biologists are pretty sure this sort of thing happened long ago when the first eukaryotic cells evolved. Evidence for the Plausibility of an Endosymbiotic Origin of Eukaryotic Organelles