16 jun Back to the basics.

Based on what I’ve read in evolutionary history RNA molecules most people believe, predate DNA molecules. So in the early stages. So in the early stages you had a lot of change and so uracil molecules were just fine and there was a lot of errors and whatever else. 

But then information needed to be a little more persistent and a little less error prone, well then thymine helped stabilise things. Why then has uracil stuck around, well RNA molecules they have all these roles in cells. Messenger RNA molecules are taking information from the DNA and getting it transcribed or getting it translated at the ribosome, but they shouldn’t hang out forever. You actually want them to be some what unstable.