Ok, I'm back, I apologise for my absence from this thread. I've was extremely busy Friday night and yesterday.
Anyway slimebeast, to answer your question on why hasn't bacteria evolved into any forms of higher life in a little more detail as promised.
Well the truth is they do, it's just that you have chosen this argument based solely on the fact that you know evolution is an extremely slow process and so we can't give examples that have been directly observed for such a large evolution. An evolution from unicellular life to multicellular life is massive, it takes literally hundreds of million of years to occur. It's like asking to see how a star system forms, it would be impossible to show as it exists on such a large time-scale. We can only give you snapshots of this evolution, as opposed to give the complete story.
Unicellular life would have evolved into multicellular life forms by forming colonies. A colony is a group of unicellular lifeforms of the same species which better thrive as a colonial organism. The main difference between colonial organisms and multicellular life is that a separated cell from a colonial organism can survive independently, where as a separated cell from a multicellular organism would die.
We can observe several life forms that exist in this colonial state between unicellular and multicellular life such as the sea-sponge. Sea-sponges form colonial organisms, with many unicellular organisms of the same species living closely together to form a single colonial organism, with the single cells forming specialities in a similar style to a multicellular organism. It is far more beneficial for the single cells to exist in this state than as individuals.
A whole sponge can be sifted to separate the cells. Once the cells are separated they can live independently, but will re-form with each other to recreate the colonial organism So even though the unicellular life can survive outside of the colony, it will reform a colony because it has a better chance of survival.
The evolution into a multicellular organism is when these cells evolve to grow more dependant on being in a colonial state to the point that they find it impossible to survive when they are no longer in a colony. But this process from colonial life to multicellular life is a process which takes millions of years.
Bacteria, as well a lot of other unicellular life forms, can exist in colonies, where living together as a group is more beneficial than living as an individual.
I think that you seem to think that if bacteria do evolve into a higher form of life, then it would just be a case of one day a bacteria has one cell, the next it has ten. This isn't the case.










