Evolution by natural selection.
survival of the fittest=natural selection
Answer:
The phylum platyhelminthes includes the organism like flatworms, earth worm and many other species. They play a major role in the marine, terrestrial and freshwater ecosystem. It contains a variety of nutrient sources.
Explanation:
They are of great importance from the times when there were no other organism.
Answer:
Mutations happen in our cells all the time. It's actually how all humans grow and change. The vast majority of mutations are harmless. Thus, they aren't avoidable.