Air does have weight. 14.7 psi in fact. Most of the air is Nitrogen gas, which is 2 atoms of nitrogen. There is also Oxygen gas (O2). Finally there is Carbon Dioxide (CO2). There is also a small percentage of other gasses, but they are insignificant.
I believe the answer to this question is yes it is but i am not positive <span />
The original source of all genetic variation is <span>mutation.</span>
