Because bacteria mutates that's why we have a new flu vaccine every year , because strains of DNA in the bacteria change all the time.
The answer is a the first one.
Answer:
The fish did not yet exist when the old layers of rocks were deposited. In fact, animals with hard parts did not evolve until about 600 million years ago, which is only about 13% of the 4.5 billion year age of the Earth. Multicellular animals without hard parts left tracks in older sediments, but had no fossilize-able body parts.
Explanation:
Dominate and no know preditors <span />
