Explain how dna sequences can provide evidence of evolution.

DNA can act as the evidence of evolution in many ways. It is the source of information which is carried in every next generation since a very long period of time.

This show the ancestral relationship of one organism with other. This also shows how closely related one organism is to other.

The characters that was present at long time ago will be seen today as well and by comparing the changes in the character since that period of time will also serve as evidence of evolution.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =