One of the questions I’ve had about the evolution of bacteria is why haven’t they evolved past 1 chromosome? I asked a guest speaker this morning. Bill Rourke came and talked about the techniques and importance of bacteria in life and the medical field. He said besides recombination of their chromosomes, they also share plasmids. Not sure if I’m looking at this correctly, but I see plasmids now as intentionally made viruses, so that bacteria can store more genetic information than just their one chromosome. A way of circumventing that one chromosome barrier.
The impact of bacteria on organ systems is not well understood, and is often overlooked in biological consideration. Bacteria evolve quite rapidly, and can share immunity with each other and develop resistance to antibiotics. Generations are created every few minutes. Thus the rate at which evolution occurs in bacteria should be a MAJOR influence to the co-evolution of larger animals.
I read an article somewhere recently, about how our moods can be heavily influenced by the bacteria we carry. Couples eventually end up having the same cultures and strains inside them, affecting them in similar ways. There are fecal transplants that cure gut infections 100% of the time. Transplant of healthy bacteria into an obese persons’ gut can dramatically affect behavior and diet choices. Science is still in its infancy, and bacteria are certainly one of the things we don’t fully understand yet.