Because bacterial life cycle is very short it complete in 20 minutes to produce copies. secomdly bacterial genome is simple to be handle.
Wood, when dry, stores chemical energy. This chemical energy is released as the wood burns, and it is converted into heat, or thermal energy. This also produces light energy. As a result of burning, the wood turns into an entirely new substance - ashes. Wood, a form of fuel with lots of potential energy stored in its covalent bonds, will react with molecules of oxygen in the air in a dramatic chemical reaction we call fire. The complex molecules in the wood have 'high energy' covalent bonds, as do the molecules of oxygen.
I hope this helped:))
B. Clade 1 is ancestral to all the other clades